The Palace of Holyroodhouse in Edinburgh is the Queen's official residence in Scotland. The site was founded as an Augustian Monestry in 1128 by David I, after he had a vision of a stag with a rood or cross on its forehead. In 1501 James IV built a palace close to the Abbey. The Palace was home to Mary Queen of Scots from 1561-1567. It also played host to Cromwell's troops during the English Civil War, during which time it suffered extensive fire damage. It was significantly rebuilt and extended by Charles II, though he never stayed there. In 1745 Bonnie Prince Charlie held court there after seizing control of Edinburgh. Its use as a Royal residence was revived by Queen Victoria. Holyrood Abbey stands next to Holyrood Palace. The Abbey can be traced back to a monastery founded by David I in 1128. The Abbey was badly damaged during the Reformation. It was finally abandoned in 1768 after the roof collapsed. Arthur's Seat is the remains of a now extinct volcano which rises 250 metres (823 feet) above Holyrood Park in Edinburgh. Remains of an Iron Age Hill fort were found on the east side of the hill. The origins of the peak's name have been somewhat lost. One theory is that it is a corruption of the gaellic Ard-na-saith, meaning height of arrows, indicating a past usage as a practice place for archery. Arthur's Seat is also known as the Lion's Head. Salisbury Crags were formed by a combination of volcanic activity and glacial erosion. James Hutton's studies of the Crags formed an important part of his 1788 work 'Theory of the Earth', the book that earned him his reputation as the founder of modern geology.