Main Gate Park

Replica of the gatehouse that sealed Los Alamos from the outside world during the Manhattan Project

Main Gate Park stands at the original entrance to the secret Manhattan Project site, and its small building is a reconstruction of the guard gatehouse through which every resident had to pass. During the Project years, the gate separated the classified community from the outside world: incoming visitors were scrutinised, outgoing mail was read, and the entire site was fenced and guarded.

The park has interpretive panels explaining the security apparatus of wartime Los Alamos and photographs of the original gate. It is a small stop — fifteen minutes is enough — but it adds a physical dimension to the history that the museums can't quite replicate.

things to do sight
A story
During the Manhattan Project years (1943–1945), Los Alamos did not officially exist. Mail was addressed to "P.O. Box 1663, Santa Fe." Residents could not tell anyone where they lived. All correspondence was censored. Scientists who had been accustomed to free exchange of ideas found themselves confined to a fenced plateau, their movements tracked and their conversations monitored. Several, including Klaus Fuchs, used that isolation to pass information to the Soviet Union.