was built in 1911 as a replacement for the 1680 lighthouse in the centre of St Agnes. The lighthouse was converted from acetylene gas to electricity in 1992 and the original range of 17 nautical miles was reduced to nine in 2011. The headland is within the Isles of Scilly Area of Outstanding Natural Beauty and part of the Heritage Coast. It is also a Geological Conservation Review site for its Quaternary geomorphology and was first designated a Site of Special Scientific Interest (SSSI) in 1971 for both its biological and geological interests. Porthellick Cove Porthellick Cove contains a memorial to mark the spot where the body of Admiral Sir Cloudesley Shovell was washed ashore after the 1707 Scilly naval disaster. This was one of the greatest maritime disasters in British history, when four ships (Association, Firebrand, Romney and Eagle) with nearly 2,000 sailors were lost. Other locations The following is a list of some other locations on St Mary's: Lower Moors Nature Reserve Higher Moors Nature Reserve (see Porth Hellick) Holy Vale Porthloo Beach Watermill Cove Innisidgen Burial Chamber Isles of Scilly Golf Club, near Telegraph and Porthloo Population 1841 – 1,519 plus 26 in the Garrison 1861 – 1,424 1871 – 1,368 1881 – 1,290 1891 – 1,201 1901 – 1,355 1911 – 1,376 1921 – 1,196 1931 – 1,216 1951 – 1,625 1961 – 1,736 1971 – 1,958 1981 – 2,073 1991 – 1,600 2001 – 1,666 2011 – 1,723 Education Five Islands Academy (previously Five Islands School) has a combined primary and secondary campus in St. Mary's. A boarding house, Mundesley Boarding House, serves secondary students from other islands. Students at the sixth-form college level reside and board elsewhere, in mainland Great Britain. Previously the Learning and Skills Council paid for costs of accommodation for sixth-formers. St. Mary's Library is located at the Porthcressa seafront. Carn Gwaval Wellbeing Centre has adult further education programmes. See also List of shipwrecks of the Isles of Scilly List of windmills in Cornwall#Isles of Scilly References External links Isles of Scilly Wildlife Trust Inhabited islands of the Isles of Scilly Civil parishes in Cornwall