When the first atomic bomb was dropped on the Japanese city of Hiroshima on August 6th, 1945, followed by a second bomb in Nagasaki three days later, the world was forever changed. Before the atomic bomb became known to the world, however, its creation was shrouded in secrecy. Though The Manhattan Project is no longer secret, the places in New York City used for research, uranium storage, and other clandestine activities are not as well known. Manhattan Project isn’t a codename, rather it was issued using standard Army Corps of Engineers naming practices which were based on primary research locations. Lieutenant General Leslie Richard Groves, Jr., director of the project, came up with the name Manhattan Engineer District, which was plain enough to not attract attention. It was then naturally shortened to the Manhattan Project. As the project grew, research, testing, and construction spread out to other areas of the country, mostly notably Oak Ridge, Tennessee, and Los Alamos, New Mexico. The earliest days of the project however were based right here in New York City.

This weekend, as Christopher Nolan’s summer blockbuster Oppenheimer continues to play on theater screens, the world will mark the 78th anniversary of the bombings at Hiroshima and Nagasaki. Here, we uncover 8 sites connected to the Manhattan Project and the tragic events of August 6th and 9th, 1945.

1. 270 Broadway

270 Broadway, former site used in the Manhattan Project
A view looking down Broadway with 270 in the middle on the left-hand side

In 1942, the 18th floor of 270 Broadway is where the first offices occupied by engineers on the Manhattan Project were located. This is where the North Atlantic Division of the Army Corps of Engineers was headquartered at the time and where the project got its name. Built in 1930, the building is now occupied by office, retail, and residential spaces. In 1943, the headquarters of the Manhattan Project moved to Oak Ridge, Tennessee.