Sully Island

Sully Island (Welsh: Ynys Sili) is a small tidal island of 14.5 acres (5.9 ha) by the hamlet of Swanbridge in the Vale of Glamorgan. It is located 400 m (440 yd) off the northern coast of the Bristol Channel, midway between the towns of Penarth and Barry and 10 km (6 mi) south of the Welsh capital city of Cardiff. It is part of the parish of Sully, after which it is named, and is registered as a Site of Special Scientific Interest. Sully island is one of 43 (unbridged) tidal islands that can be reached on foot from the mainland of Great Britain.^[1]

Access to the island is on foot at low tide from the car park of the Captain's Wife public house. A rocky causeway connecting the island to the mainland is uncovered for approximately 3 hours either side of low tide, the island being cut off from the mainland for the rest of the day. A tide table is displayed to indicate when it is safe to cross.

During the 13th century, the island was the base for Alfredo de Marisco,^{[citation needed]} a Norman pirate known locally as The Night Hawk. In the Middle Ages the island was well known for its involvement in the local smuggling trade.