Castle Williams

Castle Williams stands as a circular red sandstone fortification measuring 40 feet high and 210 feet in diameter at the west point of Governors Island.

Lieutenant Colonel Jonathan Williams designed and constructed this coastal defense structure between 1807 and 1811 to protect New York Harbor from British naval threats.

The fort transitioned from a military stronghold to a prison facility during the Civil War, housing both Union troops and Confederate soldiers in its thick-walled chambers.

The National Park Service maintains the fort as part of Governors Island National Monument, with plans to provide increased public access through guided tours.

The fort features multiple levels of enclosed gun emplacements within its 8-foot-thick walls, establishing a new standard for American coastal fortification design.

Location: Manhattan

Inception: 1807

Elevation above the sea: 0 m

Height: 12 m

Website: https://nps.gov/gois/learn/historyculture/castle-williams.htm

GPS coordinates: 40.69278,-74.01917

Latest update: September 18, 2025 07:58