This 9m high, stone tower with a tapering top was built by Colonel James Hughes of Lys Dulas in 1821 as a landmark and also as a refuge for sailors shipwrecked on the island. The tower was supplied with essential foodstuffs to provide aid and comfort until the sailors could be rescued. A tablet on the tower is inscribed '1821, Col. James Hughes owner'.

Sources include:
Holden, C, 2008, The Essential Underwater Guide to North Wales, Vol 2, pg136
Historic Admiralty Chart 1170-A4, RCAHMW Digital Collections sourced from UK Hydrographic Office (published 1839)

RCAHMW, October 2011.