Los Alamos: Tour Behind the Fence

Los Alamos Sites 

Nearly all the park’s historic properties at Los Alamos are located “behind the fence” on a secure federal Department of Energy reservation. Visitors must be on a guided tour offered by Los Alamos National Laboratory to visit these historic buildings. These tours are only offered three times a year. Reservations are required. The tours take visitors to three historic buildings including Pond Cabin, a building that Nobel Laureate Emilio Segrè and his team used. Visitors will also see Battleship Bunker, a building used for implosion diagnostic testing, and the Slotin Building where physicist Louis Slotin succumbed to a deadly criticality accident. 

Trinity Site 

On July 16, 1945, at 5:29 am Mountain War Time, scientists and military officials detonated the world’s first atomic device, known as the “Gadget.” The location of this test, known as the Trinity Site, is located on White Sands Missile Range and is closed to the public. Twice a year, the US Army hosts a Trinity Site Open House when the public may visit Trinity Site.  

Scroll down for sites that are only available through guided tours 

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    Last updated: February 15, 2023

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    Manhattan Project National Historical Park
    c/o NPS Intermountain Regional Office
    P.O. Box 25287

    Denver, CO 80225-0287


    Hanford: 509.376.1647
    Los Alamos: 505.661.6277
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