Scilly Islands (sĭlˈē) [key], officially Isles of Scilly, archipelago and unitary authority (2001 pop. 2,153), encompassing more than 150 isles and rocky islets, off Cornwall, SW England, 28 mi (45 km) from Land's End. The archipelago has been politically separate from Cornwall since 1890. On the rocky coasts, marked by lighthouses and lightships, scores of ships were wrecked, notably Sir Clowdisley Shovell's fleet in 1707. The mild climate and heavy rainfall provide a flourishing environment for subtropical plants. Market flower growing is one of the leading occupations. Vegetable production and tourism are also economically important. Five of the isles are inhabited—St. Mary's, Tresco, St. Martin's, St. Agnes, and Bryher. On the largest, St. Mary's, is the capital, Hugh Town, built around the late 16th-century Star Castle. Originally constructed by order of Elizabeth I as a defense against the Spanish and pirates, the castle is where Prince Charles (later Charles II) stopped in 1645 on his flight to Jersey; it is now a hotel. Hugh Town is also the site of a museum that displays many of the archaeological remains discovered on the islands. On Tresco are Oliver Cromwell's Tower, ruins of a 10th-century abbey, King Charles's Castle (1554), the 19th-century Abbey Garden with exotic plants that flourish in the mild climate, and the residence of the lord proprietor of the islands. The isle of Samson has ancient stone monuments.