Castle Williams

Castle Williams is a circular fortification made of red sandstone located on the western side of Governors Island. The structure contains gun emplacements at multiple levels that are built into its thick walls.

The fort was built between 1807 and 1811 as a defense against British naval threats. It was later repurposed as a prison and played a role during the American Civil War.

The fort served as a military installation and later as a detention facility, with its circular design reflecting early 19th-century military thinking. Visitors can see how the thick walls and enclosed spaces shaped daily life for soldiers and prisoners alike.

The fort is located on Governors Island and reached by ferry from the Financial District. Visitors should wear comfortable shoes since exploring multiple levels and exposed areas is involved.

The fort was designed by Jonathan Williams, a military engineer who created new standards for American coastal fortification design. His innovative methods for protecting New York Harbor were later copied in similar fortifications across the country.

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: December 7, 2025 19:32