Fort Jay is a historic military fort located on Governors Island in New York Harbor. Built in the late 18th century, it was named after John Jay, the first Chief Justice of the United States. The fort played a significant role in the defense of New York City during various conflicts, including the War of 1812 and the Civil War. The fort features a star-shaped design and is surrounded by a moat. Today, Fort Jay is part of the Governors Island National Monument, which preserves its historical significance and offers visitors a glimpse into military history and architecture.