Without a badge from the office at 109 East Palace, Santa Fe, no one was admitted inside the gates of the Manhattan Project. Military guards were on duty at all hours. PHOTOGRAPH CREDIT: Los Alamos Historical Society Archive.

From the press release:
Rubensteinís Critical Mass featured in upcoming ĎAtomic Historiesí Exhibition



Note: Representative image at left is often cropped for display purposes. Downloaded high-resolution images are not cropped.