The Indian Rocks Causeway (also called the Indian Rocks Bridge) is a twin-span double-leaf bascule bridge that crosses the Narrows, part of the Gulf Intracoastal Waterway, connecting the barrier islands of Indian Rocks Beach and the mainland of Largo, Florida. The bridge carries Walsingham Road, part of SR 688. The eastbound span of the Indian Rocks Causeway was built in 1958, replacing the original swing bridge built in 1916, and the westbound span was built in 1999.[1][2][3]