Rufus Castle, standing over Church Ope Cove was built for William II of England (also known as William Rufus) soon after the conquest of England by his father William the Conqueror. None of that castle remains; the existing casle dates from the 15th century. In 1539 King Henry VIII ordered the construction of Portland Castle for defence against attacks by the French; the castle cost £4,964. It is one of the best preserved castles from this period, and is opened to the public by the custodians English Heritage. In the 17th century, chief architect and Surveyor-General to James I, Inigo Jones, surveyed the area and introduced the local Portland stone to London, using it in his Banqueting House, Whitehall, and for repairs on St Paul’s Cathedral. His successor, Sir Christopher Wren, the architect and Member of Parliament for nearby Weymouth, used six million tons of white Portland limestone to rebuild destroyed parts of the capital after the Great Fire of London of 1666. Well-known buildings in the capital, including St Paul’s Cathedral and the eastern front of Buckingham Palace feature the stone. After the First World War, a quarry was opened by The Crown Estate to provide stone for the Cenotaph in Whitehall and half a million gravestones for war cemeteries, and after the Second World War hundreds of thousands of gravestones were hewn for soldiers who had fallen on the Western Front. Portland cement has nothing to do with Portland; it was so named due to its similar colour to Portland stone when mixed with lime and sand.