Lottery for tour of Manhattan Project National Historical Park opens June 15

Los Alamos National Laboratory, in collaboration with the National Nuclear Security Administration’s Los Alamos Field Office and the National Park Service, is opening the lottery for its second 2025 series of public “behind-the-fence” tours of Manhattan Project National Historical Park. Tours will take place twice each day Oct. 14, 15 and 16.

How the lottery works:

• Registration period is open June 15-28
• Register online
• Participants will be drawn at random July 1 from the pool of registrants
• All registrants will be notified of the results via email
• If you registered for the lottery in the past but were NOT chosen, you must register again for the October 2025 round of tours

These unique, half-day tours take participants to sites where Manhattan Project scientists made world-changing discoveries. Visitors will:

• Visit the original Pond Cabin, where physicist Emilio Segre’s team made the pivotal discovery that the “Thin Man” plutonium bomb design would not work.
• See the bunker where experiments helped determine whether the Trinity nuclear test would succeed.
• Walk through the Slotin Building, where a fatal criticality accident transformed the safety culture of Los Alamos National Laboratory.
• Hear from experts about what life was like in Los Alamos when it was a secret city during World War II.

Participants must be at least 18 years old, U.S. citizens, and able to provide proof of citizenship at tour check-in. As an active national security laboratory, Los Alamos National Laboratory has strict entry requirements for visitors; read registration materials carefully for details. These tours are not open to Lab employees.

Lottery registration is online only. To register, visit the MAPR@LANL website. All future tour opportunities, as well as ongoing park updates, will be posted here also.

Visit the National Park Service’s Manhattan Project National Historical Park website, and the Los Alamos History Museum for more information on the park.  

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