The Poder is an 8-pound cannon cast in Peru in 1673. Originally emplaced at the Castillo de San Joaquin to guard the entrance to the San Francisco Bay, the cannon was subsequently moved to Sonoma at the request of the Mexican Governor of Alta California.
On July 20, 1846, Captain Montgomery of the U.S.S. Portsmouth sent a military detachment to retrieve the cannon and return it to the Presidio.
The Poder is located outside of the Officers' Club, Building 50.