Sully Island

Sully Island is a tidal island in the Vale of Glamorgan covering around 6 hectares, with rocky cliffs, grassy paths, and a natural causeway linking it to the shore. The site shelters diverse habitats and supports rare species of plants and animals in its protected landscape.

The island served as a base for Norman pirate Alfredo de Marisco in the 13th century, later becoming a center for smuggling activities. The Antarctic vessel SY Scotia wrecked near its shores in 1916, leaving traces in the region's story.

Archaeological discoveries reveal a Saxon promontory fort and Bronze Age barrow on the eastern end, indicating early human settlements on the island.

Access to the island requires careful timing, as the rocky causeway remains visible for about three hours during low tide. It is wise to check tide tables and familiarize yourself with local conditions before planning your visit.

The wreck of Antarctic vessel SY Scotia near the island led to local children collecting coal from its remains for many years afterward. This maritime episode left a vivid memory in the local community.

Location: The Vale of Glamorgan

GPS coordinates: 51.39501,-3.19725

Latest update: December 8, 2025 19:58