The Isles of Scilly are an archipelago off the Cornish coast, in southwest England. The islands are covered in heathland, and fringed by sandy beaches such as Great Bay on St. Martin’s. On Tresco, one of the 5 inhabited islands, Tresco Abbey Garden is home to subtropical plants and also the Valhalla Museum, displaying shipwrecked figureheads. The tower of 17th-century Cromwell’s Castle stands at the north of Tresco.