Battery Townsley

Battery Townsley contains a network of 26 underground rooms protected by concrete walls measuring up to 14 feet in thickness.

The military complex, constructed between 1938 and 1940, housed two 16-inch caliber guns capable of launching 2,100-pound projectiles across 25 miles of ocean.

The structure represents mid-20th century coastal fortification engineering and serves as an educational center for military defense history.

Visitors reach the battery through a steep half-mile walk from Fort Cronkhite parking lot, with guided tours available on the first Sunday of each month.

The facility conducted experiments simulating nuclear explosion pressures from 1965 to 1974, marking its transformation from artillery placement to research center.

Location: Marin County

Address: Fort Cronkhite, Mill Valley, CA 94941, USA 94941 Mill Valley

Opening Hours: Tuesday 10:00-17:30; Thursday 10:00-17:30; Saturday-Sunday 10:00-17:30

Phone: +14153311540

Website: http://nps.gov/goga/historyculture/battery-townsley.htm

GPS coordinates: 37.83586,-122.54350

Latest update: June 17, 2025 11:14