Mount Diablo Beacon

Mount Diablo Beacon: EIM
Left Dark by War, Lighted in Remembrance
A large flashing light atop this rotunda once
guided airplanes flying through the night skies
of the Bay Area. Originally held aloft on a 75-
foot tower erected by Standard Oil in 1928, it
served as a crucial route-finding aid in the days
before electronic navigation. Civilian Conservation
Corps workers crowned this building with the
10-million candlepower light before the outbreak
of World War II. After the 1941 attack on Pearl
Harbor it was turned off amid fears it could guide
the enemy in attacking the mainland.
Obsolete after the war, the beacon remains dark
except for an annual December 7th lighting in
memorial to those who died at Pearl Harbor.