South Stack South Stack South Stack () is an island situated just off Holy Island on the northwest coast of Anglesey. South Stack is famous as the location of one of Wales' most spectacular lighthouses, South Stack Lighthouse. It has a height of 41 metres (135 feet). It has a maximum area of 7 acres. Until 1828 when an iron suspension bridge was built, the only means of crossing the deep water channel on to the island was in a basket which was suspended on a hemp cable. The suspension bridge was replaced in 1964, but by 1983 the bridge had to
Ramsey Island fourth largest island in Wales, after Anglesey, Holy Island and Skomer. The island has a diverse geology for a relatively small area; it comprises sedimentary, volcanic and intrusive igneous rocks dating from the early Palaeozoic Era. The larger part of the north of the island is formed from mudstones of the Tetragraptus Mudstone Formation (also known as the 'Penmaen Dewi Shale Formation' and again as the 'Road Uchaf Formation' (sic) after the Rhod Uchaf locality on the island's east coast). However Carnysgubor stands proud to their west as it is formed from a more resistant microtonalite intrusion. In contrast the