Steep Holm (Welsh: Ynys Rhonech, Old English: Ronech and later Steopanreolice) is an English island lying in the Bristol Channel. The island covers 48.87acre at high tide, expanding to 63.26acre at mean low water. At its highest point it is 78m above mean sea level. It lies within the historic boundaries of Somerset and administratively forms part of North Somerset. Between 1 April 1974 and 1 April 1996 it was administered as part of Avon. Nearby is Flat Holm island (Welsh: Ynys Echni), part of Wales. The Carboniferous Limestone island rises to about 200ft and serves as a wind and wave break, sheltering the upper reaches of the Bristol Channel. The island is now uninhabited, with the exception of the wardens. It is protected as a nature reserve and Site of Special Scientific Interest (SSSI) with a large bird population and plants including wild peonies. There was a signal station or watchtower on the island in Roman times, but there may have been human habitation as early as the Iron Age. In the 6th century it was home to St Gildas and to a small Augustinian priory in the 12th and 13th centuries. An inn was built in 1832 and used for holidays in the 19th century. A bird sanctuary was established in 1931 and since 1951 has been leased to charitable trusts. It is now owned by the Kenneth Allsop Memorial Trust. In the 1860s the island was fortified with ten 7-inch rifled muzzle loaders as one of the Palmerston Forts for the coastal defence of the Bristol Channel until it was abandoned in 1898. The infrastructure was reused in World War I and II when MarkVII6-inch breech-loading guns and search lights were installed. To enable the movement of materials, soldiers from the Indian Army Service Corps initially used mules and then installed a cable-operated winched switchback railway.
