Manhattan Project Historical Marquee behind Fence Opt

Behind-the-Fence Tours

Manhattan Project National Historical Park Tours

Go behind the scenes of America’s atomic history with exclusive access to secure sites at Los Alamos National Laboratory.

Take a rare opportunity to go "behind the fence" at Los Alamos National Laboratory, where select guided tours offer access to secure areas not typically open to the public. These tours are offered twice a year with advance registration and limited capacity. The most up-to-date information about these tours will always appear on this page.

During your visit, you'll see:

  • Pond Cabin – Former office of Emilio Segrè’s Radioactivity Group studying plutonium.
  • Battleship Bunker – Used to protect staff and equipment during explosives testing for implosion design.
  • Slotin Building – Site of physicist Louis Slotin’s criticality accident.

Upcoming Tour Dates

Each tour lasts approximately four hours, with two tours offered per day and a maximum of 30 participants per tour.

May 2025 Tours

  • May 13
  • May 14
  • May 15

October 2025 Tours

  • October 14
  • October 15
  • October 16

Registration & Lottery Process

May Tours:

Registration is full

October Tours:

Registration will open in June. Dates to be announced here.
Note: All registrations are conducted via an online lottery system.

Visitor Eligibility & Requirements

Due to security protocols at Los Alamos National Laboratory, all visitors must meet strict eligibility criteria before confirming tour participation.

Participants must:

  • Be U.S. citizens with original documentation (birth certificate, passport, tribal ID, or other qualified document).
  • Be at least 18 years of age.
  • Be able to walk short distances, stand for 30 minutes, climb stairs, and traverse over uneven surfaces.
  • Wear sturdy footwear and long pants.
  • Not bring cell phones, cameras, Bluetooth devices, or any type of recording devices.
  • Comply with all additional requirements outlined during registration.

To learn more about the Manhattan Project and other historic sites in the Los Alamos area, visit our Plan Your Visit page.