Register Feb. 19-26 for a behind-the-fence tour of Manhattan Project National Historical Park this spring

The registration lottery for guided, behind-the-fence tours of Manhattan Project National Historical Park opens Feb. 19. The tours are offered by Los Alamos National Laboratory in collaboration with the National Nuclear Security Administration’s Los Alamos Field Office and the National Park Service on May 13, 14 and 15. 

These unique, half-day tours take participants to sites where Manhattan Project scientists made history. Step inside the original Pond Cabin, where physicist Emilio Segrè’s team made the pivotal discovery that the Thin Man plutonium bomb design would not work. Descend into a bunker where experiments helped determine whether the Trinity nuclear test would succeed. See the Slotin Building, where a fatal criticality accident transformed the safety culture of Los Alamos National Laboratory. And hear from experts about what life was like in Los Alamos when it was a secret city.

Participants for the May tours will be selected via a random lottery and notified in early March. Registration for the lottery opens Feb. 19 and closes Feb. 26. All lottery entrants will receive an email informing them of the results. 

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 on the same page.

The next series of tours takes place Oct. 14, 15 and 16. A separate lottery will be held for these later in 2025.

Even if you don’t make the tour via the lottery, there are plenty of additional ways to visit Los Alamos, New Mexico and see Manhattan Project history where it happened.