Castle Williams

Castle Williams is a distinctive circular red sandstone fortress constructed between 1807 and 1811 on Governor's Island in New York Harbor. Designed by Lieutenant Colonel Jonathan Williams, Chief Engineer of the U.S. Army Corps of Engineers, the fort features forty-foot-high walls and eight-foot-thick ramparts that once bristled with over one hundred cannons. Its innovative design influenced coastal fortifications for decades and proved so formidable that British forces never attacked New York City during the War of 1812. Now part of the Governor's Island National Monument under National Park Service stewardship, the structure nicknamed "the Cheesebox" for its distinctive shape attracts visitors interested in 19th-century military architecture and American defense history.