Manhattan Project Sites

Visiting the major sites associated with WWII's Manhattan Project and the creation of the nuclear bomb.

President Roosevelt authorized the Manhattan Project on December 28, 1942. This ultra-secret project led to the the world's first uranium atomic bomb (dropped on Hiroshima, Japan, on August 6, 1945) and the world's first plutonium bomb (dropped on Nagasaki, Japan, on August 9, 1945); ultimately ending WWII. The sites on this quest are associated with the 1940s Manhattan Project and were chosen to give us a better understanding of this period of history and the ramifications therefrom. We have narrowed down the list of sites on the quest based on various sources of information. However, the majority of the sites and the information on this page is taken primarily from the Atomic Heritage Foundation.

1. Pupin Physics Laboratories (Columbia University, New York) - Pupin Hall is also where Enrico Fermi, Leo Szilard, and other physicists began work on developing a self-sustaining neutron chain reaction in 1939, in the basement (five levels below the entrance). The work was moved to the University of Chicago after Pearl Harbor (so it would be safer from attack from the Atlantic), it was called the Manhattan Project because of where it had begun, and it kept its name when it moved later to Los Alamos, New Mexico.

2. First offices of the Manhattan Project (Manhattan, NY) - Located at 270 Broadway, Manhattan, NY. (It appears this is where the Arthur Levitt State Office Building is now). This location was the first Headquarters of the Manhattan Engineers District (MED) from mid-June 1942 to August 1943, when it shifted to Oak Ridge, Tennessee.

3. 2nd Headquarters for MED (Washington, DC) - Among Col. Leslie Groves’ early and swift actions in his role as head of the MED was to move the permanent project headquarters from New York to Washington, D.C. He chose the fifth floor of what was then known as the New War Department Building. Located at 2201 C Street, NW, it was the latest of a number of office locations that had been co-opted by the growing War Department. While traveling to oversee various project details at sites around the country, Groves would continue to control the details of the Manhattan Project out of his small two-room office at the War Department building throughout the war. After World War II, the building was turned over to the State Department, and became home to the office of the Secretary of State. It was unofficially known simply as the State Department Building or the Main Street Building, until September 2000, when it was renamed after President Harry S. Truman.

4. Baker and Williams Warehouses (Manhattan, NY)- West 20th Street, Manhattan - used by the MED in the early 1940s for the short-term storage of tons of uranium concentrates that had been shipped in secret to the nearby Hudson River Docks. Came from the Eldorado Mines in Canada.

5. Staten Island Uranium Warehouse (Staten Island, NY) - The US secured 1,200 tons of Congolese uranium, which was stockpiled on Staten Island, New York, US, in the shadow of the Bayonne Bridge. The Staten Island uranium warehouse was arranged by Edgar Sengier. Sengier was a Belgian businessman and director of Union Minière du Haut Katanga, a company that owned the world’s largest uranium mine in the Belgian colony of Congo called Shinkolobwe. Sengier had been buying uranium since the start of tensions in Europe, sensing that the material would be critical in the development of atomic weapons. His personal uranium stockpile remained hidden on Staten Island for three years before it was purchased for Manhattan Project in September 1942. It was then shipped to Los Alamos by train. Sengier later became the only non-US citizen to win the Medal of Merit award from the United States for “services in supplying material.” In 2008, the Environmental Protection Agency visited 2351 Richmond Terrace, the address right under the bridge. Today, there’s little to see along this stretch of Richmond Terrace. A couple of abandoned trailers and a pile of old tires litter a vacant lot shared with a local paving company.

6. Uranium Reactor (Oak Ridge, TN) - Oak Ridge was the home of the uranium enrichment plants (K-25 and Y-12), the liquid thermal diffusion plant (S-50), and the pilot plutonium production reactor (X-10 Graphite Reactor). The X-10 Graphite Reactor was the first reactor built after the successful experimental “Chicago Pile I” at the University of Chicago. On December 2, 1942, using a lattice of graphite blocks and uranium rods, Enrico Fermi proved that a nuclear chain reaction could be controlled. Scientists knew that it would only be a matter of time before the energy of the atom could be harnessed for a bomb. A series of huge underground concrete cells, the first of which sat under the pile, extended to one story above ground. Aluminum cans containing uranium slugs would drop into the first cell of the chemical separation facility and dissolve and then begin the extraction process. The moment everyone had been waiting for came in late October 1943 when DuPont completed construction and tests of the X-10 pile. After thousands of uranium slugs were loaded, the pile went critical in the early morning of November 4th and produced its first plutonium by the end of the month. Criticality was achieved with only half of the channels filled with uranium. During the next several months, Compton gradually raised the power level of the pile and increased plutonium yield. Chemical separation techniques using the bismuth phosphate process were so successful that Los Alamos received its first plutonium samples beginning in the spring of 1944. Fission studies of these samples at Los Alamos during the summer heavily influenced bomb design.

7. Uravan (Grand Junction, CO) - the 55 acre gravel mine Philip Leahy bought to establish a uranium refinery. Uranium ore extracted from the surrounding area would be brought to Uravan and run through the plant to produce green uranium “sludge”. This refinery was the only domestic uranium procurement site from 1943-1946. With no mill of its own to process the material, the MED signed a top-secret contract with the United States Vanadium Corporation to operate its plant in Uravan for uranium procurement. The MED agreed to build an additional mill to help process the material. Beginning in May 1943, the region’s uranium ore would be brought to Uravan and run through the plant to produce three tons of green uranium “sludge” per day. This material was then transported, along with similar sludge from USV’s mine in Durango, to the MED’s newly constructed refinery in Grand Junction.

8. Wendover Airfield (Wendover, UT) - Wendover Airfield was selected as the training and test center for the atomic bomb delivery group as part of Project Alberta. Nicknamed "Kingman," the site was the initial training ground for the 509th Composite Group and the 216th Army Air Force's Base Unit Special Airfield. In September 1944, Lt. Col. Paul Tibbets selected Wendover Air Force Base as the training site for the 509th Composite Group; the handpicked B-29 unit that would drop the atomic bombs. The 509th Composite Group was activated on December 17, 1944 and included over 1700 officers and men, including a team of civilian and military scientists. Named Project W-47, the Flight Test Section and the Special Ordnance Detachment helped weaponize the atomic bomb by collaborating with Los Alamos scientists to test out prototype bombs in the shape of Little Boy and Fat Man to furnish information on ballistics, electrical fusing and detonators, release mechanisms, and flying characteristics of the aircraft. Wendover proved to be an excellent place to practice these "pumpkin bomb" drops, as they were soon referred to. The unique shape of the atomic bombs required aircrews to learn new bomb drop techniques. Hundreds of practice bombs were dropped from B-29s as engineers from Los Alamos sought to determine the correct weight distribution and shape of the aerodynamically unique bombs. Special pits were also constructed with hydraulic lifts to hoist the huge bombs into the bomb bay. Between October 1944 and August 1945, 155 test units were dropped on targets surrounding the airfield at Wendover. The Enola Gay Hanger is located here.

9. Hunter’s Point Naval Shipyard (San Francisco, CA) - where the uranium bomb (Little Boy) was loaded onto the USS Indianapolis. On July 16, 1945, hours after the Trinity Test in New Mexico, the ship set sail. After stopping at Pearl Harbor, Hawaii, on July 19, 1945, it then left for Tinian, where it delivered the bomb on July 26, 1945, a few days early. The Shipyard is now the Naval Radiological Defense Laboratory. You can see the area from the Candlestick Point State Recreation Area.

10. Bockstar (Dayton, OH) - On August 9, 1945, the B-29 Bockscar dropped the Fat Man plutonium bomb on Nagasaki, Japan. On display at the National Museum of the US Air Force in Dayton, OH.

11. Burial Site of Chicago Pile-1 (Chicago, IL) - The original site of both Argonne National Laboratory and the Site A/Plot M Disposal Site, Red Gate Woods is the burial grounds of Chicago Pile-1, the world's very first nuclear reactor, as well as other reactors that were built and then buried under the watchful eye of the Manhattan Project.

12. The Shinran Statue (Manhattan, NY) - Shinran was a Japanese Buddhist monk that lived between 1173 and 1263. Today, you can find a fifteen foot bronze sculpture of him in front of the New York Buddhist Church on Riverside Drive between 105th and 106th streets. It once stood in front of a Buddhist temple in Hiroshima, Japan, a place where three waterfalls flow. On August 6th, 1945, this area was located less than 2.5 km from ground zero of the first nuclear bomb to be “used as weapon.” On the day when over 150,000 people died and 90 percent of the buildings in Hiroshima collapsed or burned–the Shinran statue persevered. Reverend T. Kenjitsu Nakagaki of the New York Buddhist church says of the piece, “The statue stood alone in the middle of all the burning. This gave the people some kind of hope. It is now the focus of an annual peace gathering held on August 5th when a bell is tolled at 7:15 p.m. At that moment in Japan, it is 8:15 a.m. on August 5th, the hour that the bomb was dropped.”

1. Ames Laboratory (Ames, IA) - uranium production methods were developed and the Burlington Atomic Energy Commission Plant - where atomic weapons were first assembled by the AEC. The Ames Project accompanied the Manhattan Project’s existing physics program. Was responsible for producing high purity uranium from uranium ore and here they created a new method for reducing and casting uranium metal. Provided 2 tons (1/3) of the uranium used in the first self-sustaining nuclear reactions at the University of Chicago in December 1942. And produced more than 1,000 tons of uranium for the Manhattan Project between 1942 and 1945.

2. Metallurgical Laboratory (the “Met Lab”) (Chicago, IL) - located in Elkhart Hall at 1118 East 58th Street on the north side of the main quadrangle of the University of Chicago, was responsible for designing a viable method for plutonium production that could fuel a nuclear chain reaction in an atomic bomb.

3. Ryder’s on Physical Laboratory (Chicago, IL) - next door to Eckhart at 1100 East 588th Street, was where the Met Lab offices were at.

4. George Herbert Jones Chemical Laboratory (Chicago, IL) - located on the north side of the main quadrangle at 5747 South Ellis Ave, where Manhattan Project scientists first isolated and weighed a sample of plutonium in 1942 in Room 405 (which is designated as a National Historic Landmark). Some of the equipment they used for the experiment is on display in the entrance hallway of the Laboratory.

5. University of Chicago-Stagg Field (Chicago, IL) - where Manhattan Project scientists carried out the Chicago Pile-1 experiment, generating the first self-sustaining nuclear chain reaction under the West Stands of Stagg Field on December 2, 1942. The Regenstein Library was later built in this location and there are plaques by the library commemorating the Chicago Pile-1.

6. Grand Junction Department Of Energy Office (Grand Junction, CO) - the center of the secret effort to mine and refine uranium ore from the surrounding mills in the Colorado Plateau. From 1943 until 1945, Grand Junction, Colorado ,was the center of the Manhattan Project’s secret effort to mine and refine uranium ore from surrounding mills in the Colorado Plateau. By 1946, over 2,600,000 pounds of uranium oxide had been produced from Colorado Plateau material, representing 14 percent of the total uranium acquired by the Army Corps of Engineers’ Manhattan Engineer District (MED). The MED secured 86 percent of its uranium from deposits in the Belgian Congo and Canada, but General Leslie Groves insisted that an effort be made to obtain uranium from domestic sources. In 1942, Groves ordered the vanadium-processing mills in the Colorado Plateau be considered as possible sources of uranium. After discovering unused uranium in tailing piles throughout the region, the MED purchased tailings from the Colorado milling towns, Narurita, Durango, Slick Rock, Gateway, and Loma. Additionally, the MED offered confidential contracts to the Vanadium Corporation of America (VCA) and United States Vanadium Company (USV) to reprocess the tailings into uranium sludge. Groves assigned Second Lieutenant Philip Leahy to establish a domestic uranium procurement program in Grand Junction, Colorado. When Leahy arrived in Grand Junction on March 23, 1943, he purchased a $10,500, fifty-five-acre gravel mine as the site to establish a uranium refinery, due to its proximity to the Gunnison River and railroad access. Leahy split his time between an office in downtown Grand Junction and the headquarters established in an old log cabin nearby. In 1947, the AEC established the Colorado Raw Materials Office at Grand Junction, which became the primary office for uranium research during the Cold War. The office was responsible for the development of experimental uranium milling and processing techniques in the Western United States.

7. Plutonium "B" Reactor (Hanford Reach, WA) - Was being built literally as the engineers and architects figured it out. Once operational, uranium slugs would drop into water pools behind the 100-B Pile after being irradiated. From these pools, the highlight-radioactive slugs would be moved by remote-controlled rail cars to a storage facility 25 miles away. The B-reactor was the first of three plutonium reactors constructed in the area during Manhattan Project.

8. The site of Project Y (Los Alamos): the top-secret atomic weapons laboratory directed by J. Robert Oppenheimer (Los Alamos, NM) - The site was so secret that one mailbox, PO Box 1663, served as the mailing address for the entire town. Here, scientists developed the Little Boy (gun-type) and Fat Man (implosion) atomic bombs. Because the name "Los Alamos" was considered classified information, the installation was variously identified as Site Y, Project Y, the Zia Project, or Santa Fe Area L. However, most residents of Los Alamos and Santa Fe simply referred to it as "The Hill." Los Alamos was so secret that it was not on any map. No one who went to live and work at Los Alamos was allowed to tell friends or family members where they were going. A single post office box, P.O. Box 1663, served all Los Alamos’s residents. Babies born during the Manhattan Project had “P.O. Box 1663” listed as their birthplace on their birth certificates. The V-site is where the world's first atomic device was assembled. Here scientists, engineers, and explosives experts worked around the clock on the "Gadget," the first plutonium-based atomic explosive. The Gun Site (TA-8-1) was where Manhattan Project scientists and engineers developed and tested the gun-type weapon design in Los Alamos, NM. The design for the Little Boy bomb dropped on Hiroshima on August 6, 1945, was developed here.

9. Trinity Site (New Mexico) - Where the first nuclear bomb was tested on July 16, 1945. On July 16, 1945, the "Gadget" nuclear device was detonated from a steel tower, exploding with a force that would forever alter human history. The mushroom cloud rose almost eight miles high and left a crater that was ten feet deep and over 1,000 feet wide. Pieces of a green, glass-like and mildly radioactive mineral were scattered in and around the crater. Dubbed “Trinitite,” investigators theorized that desert sand was lifted by the blast, liquefied by the tremendous temperature and rained down on the earth. As soon as they figured this worked, they gave the OK to the USS Indianapolis who left within hours.

10. Enola Gay (Chantilly, VA) - At 8:15 AM local time on August 6, the Enola Gay dropped the Little Boy uranium bomb over Hiroshima, Japan. Located at the National Air and Space Museum - Steven F. Udvar-Hazy Center.

1. Cavendish Laboratory (Cambridge, England, UK) - first to realize the feasibility of an atomic bomb and their rulings were vital to the development and success of the Manhattan Project in the US. Physicists carried out research on plutonium and were the first to realize that a slow neutron reactor fueled with uranium would theoretically produce substantial amounts of plutonium-239 as a by-product. They also demonstrated that plutonium would be readily “fissionalbe” by both slow and fast neutrons, making it more advantageous as a fuel source since it could be easily separated from uranium.

2. Monsanto Chemical Company (Dayton, OH) - tasked with separating an purifying the radioactive element Polonium (PO-210), which was to be used as the initiator for the atomic bombs. In order for the atomic bomb to detonate properly, the initiator had to produce neutrons within the supercritical core at exactly the right time. If the neutrons were released prematurely, the resulting explosion would be a fiddle well below the designated yield. If neutrons were released too late, the bomb may not explode at all. In 1944, a physicist proposed that Polonium-210 and Beryllium be used for an indicator device for the atomic bomb. Dayton unit I and III workers would receive the “slugs” from Oak Ridge and then the workers would separate the polonium using acid extractions methods and assembling the triggers for the atomic bomb. The Mound Cold War Discovery Center, part of the Manhattan Project, is the best place to learn about the role Dayton played in the Project.

3. Runnymede Playhouse (Dayton, OH) - acquired through eminent domain for the polonium separation process. The Bismuth slugs arrived here and kept in a shielded vault or under water in a tile-lined pool. At the Playhouse, the aluminum jackets were dissolved and the Bismuth yielded, depending on purity, between 6 and 16 grams of Polonium. Over 50 tons were processed between 1943 and 1945. In 1950, the Playhouse was so contaminated with radioactivity, parts were buried at Oak Ridge and others buried at Mound Laboratory. Dayton Project was an offshoot of the Manhattan Project.

4. (Visited 2021) Buffalo and Tonawanda, NY - Between 1942 and 1946, the Linde Air Products Division of the Union Carbide Corporation operated two facilities in upstate New York for the Manhattan Engineer District (MED). The two sites—Chandler Street, located in Buffalo, and a former ceramics plant in Tonawanda—were converted to process uranium-235, and produce nickel for the development of the gaseous diffusion barrier for the K-25 Plant at Oak Ridge, Tennessee. At the ceramics plant in Tonawanda, the MED constructed five additional buildings to refine uranium imported from the Belgian Congo and the Colorado Plateau into black oxide. The process produced around 8,000 tons of leftover sludge known as tailings. The additional liquid waste was drained into onsite wells and Tonawanda’s public sewage system, where it flowed into the Niagara River. (Notes: These two places provided for the K-25 project at Oak Ridge, which fed the Y-12 project - neither of which were terribly successful for purposes of the bombs themselves. The X-10 project was really the project that contributed).

5. (Visited 2021) Heavy Water Plants (Morgantown, WV; Newport, IN; Sylacauga, AL)- Although the plutonium production plants at Hanford would eventually use graphite as a "moderator" to slow and control the fission process, Manhattan Project officials also pursued heavy water as an alternative option. Harold Urey imagined a nuclear chain-reactor pile built as a “homogeneous” system with heavy water as both the moderator and cooler. It could function with a simple pump device, a much simpler design than the complex helium-cooled graphite pile. Urey believed such a pile could be built with only 10 tons of heavy water. The Manhattan Project soon contracted DuPont Company to build heavy water plants at three sites where ordnance works were already under construction: the Morgantown Ordnance Works near Morgantown, West Virginia; the Wabash River Ordnance Works, near Newport, Indiana; and the Alabama Ordnance Works, near Sylacauga, Alabama. (We went to the one in Sylacauga, Alabama).

6. (Visited 2018) Tinian Airfield and Atomic Bomb Pits (Tinian, Northern Mariana Islands) - Tinian Island was the launching point for the atomic bomb attacks against Hiroshima and Nagasaki, Japan. Tinian is less than forty square miles in size and located approximately 1,500 miles south of Tokyo. The round-trip flight from Tinian to Tokyo took B-29s an average of twelve hours. This proximity to Japan is one reason Tinian served as the headquarters of the 509th Composite Group. The U.S. military referred to Tinian with the codename "Destination." Six runways were completed within two months and Tinian soon became the biggest air base in the world. North Field consisted of four airfields and supported 269 B-29s. The SeaBees also built docks to accommodate the USS Indianapolis, which was steaming to Tinian to deliver atomic bomb components for "Little Boy," the bomb that dropped on Hiroshima. Completing that mission, she sailed for the Philippines. Shortly after midnight on July 30, 1945, she was torpedoed by a Japanese submarine and sank quickly. Nearly 800 of her 1200 crew members lost their lives, many allegedly to sharks. Tinian served as the forward operational base from which bombers flew to Japan. The Twenty First Bomber Command (XXI BC) launched relentless attacks on the Philippines, Okinawa, and mainland Japan. The ground literally shook as planes took off every minute of every day. Because the round trip to Japan was close to 3000 miles, all bombers that took off from the island had to be overloaded with fuel. This requirement made takeoff crashes common - a problem that planners of the atomic bomb had not anticipated. While Little Boy, a simple "gun-type" uranium bomb, would not have exploded had the Enola Gay crashed, Fat Man, a more complicated plutonium bomb that had to be fully armed before takeoff, could have. In a letter to J. Robert Oppenheimer on July 9, 1945 Columbia scientist Dr. Norman Ramsey suggested that modifications be made to the B-29s. All the bomber groups on Tinian were involved in the devastating incendiary bombing raids launched against Tokyo. The 509th Composite Group flew 51 combat missions over Japan, dropping high explosive "pumpkin bombs" over many targets. These were filled with 6,300 pounds of Composition B high explosive. The term “pumpkin bomb” applies to both the dummy concrete bombs used at Wendover, and the high explosive filled ones dropped over Japan at these targets. The dummy “pumpkin bombs” were used by the 393rd Squadron. When the group arrived at Tinian, these bombs were not used as dummy bombs, but were used as destructive forces on real targets. The pumpkin bomb missions were used for testing and training purposes, meant to prepare the Groups for future atomic missions. These bombs were similar in size, weight, and drop characterististics to the "Fat Man" atomic bomb. The intent of these missions was to carry them out as if they were the nuclear strikes with proper evasive maneuvers following the weapon release. In short, while the pumpkin bombs were meant to be used for practice, they were also still used to aim at targets throughout Japan. On August 5, 1945, a B-29 was maneuvered over a bomb loading pit and then taxied to Runway Able at North Field. At 2:45am on August 6, the B-29 - piloted by Lt. Col. Paul Tibbets of the 509th Composite Group, who had named the plane after his mother, Enola Gay - took off. On August 6 at 8:15 am Hiroshima time, the Little Boy bomb was dropped on Hiroshima. A minute later, the bomb exploded. Three days later, on August 9, the B-29 Bockscar and support planes took off from Tinian. The "Fat Man" atomic bomb exploded over the city of Nagasaki at 11:02 AM Nagasaki time. The U.S. continued to bomb Japan with conventional bombs as well. On August 14, hundreds of B-29s from Guam, Saipan, and Tinian bombed several Japanese cities, including Koromo and Nagoya. Seven B-29s with crews of the 509th Composite Group participated in the mission. The Japanese Emperor Hirohito announced the country's surrender on August 15, 1945, in his famous Jewel Voice Broadcast.

7. Hiroshima Peace Memorial Park, Shima Hospital (Hiroshima, Japan) - The target of the bombing was the Aioi Bridge, a crosswind blew the bomb to the southeast and it detonated 1,800 feet above Shima Hospital. There appears to be a small plaque there. (Uranium-Little Boy)

8. Nagasaki, Japan - The bomb missed its mark by about one mile, exploding above the Urakami section of Nagasaki. 500 feet from the hypocenter of the blast was the original Urakami Cathedral. The only thing to survive was a small part of the museum's wall: a brick pillar topped with statutes of saints. This now stands in Nagasaki just beyond the concentric rings surrounding the hypocenter. The bronze church bell also survived. The Nagasaki National Pace Memorial Hall is east of the hypocenter. It contains 70,000 lights, the approximate number of civilians killed at Nagasaki. The Cathedral was rebuilt in 1958. (Plutonium-Fat Man)

• El Dorado Mine (Port Radium) (Bear Lake, Canada) (difficult to get to and radiation issues) - hundreds of tuns of uranium ore from this mine was shipped to the US between 1942 and 1945, which was refined and delivered to Los Alamos to be used in the first atomic bomb.

• Shinkolobwe Mine (Katanga Province, Democratic Republic of the Congo) (Likely unable to visit due to safety concerns (due to both risk of collapse and radioactive contamination) and security issues (due to terrorists groups).) - The mine produced uranium ore for the Manhattan Project and was the uranium used for Little Boy bomb. Scientists learned that uranium-238 could be converted into a separate element, plutonium-239. For the fuel for atomic weapons, scientists needed fissile isotopes of uranium and plutonium. Uranium-235, which is fissile, would need to be separated from the much more common isotope uranium-238. Uranium could also be transformed into plutonium in a nuclear reactor. The demand for uranium mining and men to work those mines skyrocketed in the early days of the Manhattan Project, and would become one of its enduring legacies. Although some of the uranium came from Bear Lake in Canada – about 907 tonnes (1,000 tons) are thought to have been supplied by the Eldorado mining company – and a mine in Colorado, the majority came from the Congo. Some of the uranium from the Congo was also refined in Canada before being shipped to the US.

• Batista Field, San Antonio de los Baños Airfield (San Antonio de Los Banks, Cuba)(This is an active Cuban military airbase) - the 509th Composite Group and members of the 393rd Bombardment Squadron in December 1944 went to train on long-range, over-water flights to prepare for the long haul between Tinian and Japan. (Also the staging ground for Soviet planes during the Cuban missile crisis).