Battery Crosby

Battery Crosby stands as a relic of a time when the entrance to San Francisco Bay was considered one of the most vital strategic points in the United States. Completed in the year 1900, this fortification was built to protect the heavy underwater minefields that the military laid across the mouth of the harbor to stop enemy vessels from entering. Its primary defensive weapons were two six-inch guns mounted on sophisticated disappearing carriages. These carriages were designed to hold the guns behind thick concrete walls while they were being loaded, only raising them above the parapet for a brief moment to fire. This mechanism shielded the artillery crews from enemy return fire, allowing them to maintain a firing rate of two rounds per minute. While today it serves as a quiet vantage point for hikers and photographers, the battery remained an active military post through the height of the second world war, when it served as part of a crucial mine groupment defense system.