of a variety of native and non-native broadleaf and coniferous species. Archaeology There is evidence of prehistoric settlement on Corstorphine Hill. At the end of the 19th century, quarrying operations uncovered shells, bones, stone tools and pottery, while hammer stones, cup-marked stones, part of a quern and other pottery fragments from a kitchen midden have also been discovered. There are eleven cup-marks on the western slopes, nine in the shape of a pentagon with two in the centre. These were probably part of a sacred Neolithic or Bronze Age site, but their precise purpose is unknown. Geology Corstorphine Hill is made up primarily of dolerite, a hard, crystalline igneous rock, sitting above softer, more erodible sedimentary rocks. The hill was shaped by west-to-east flowing glaciers during the Pleistocene period, forming steep cliffs of doleritic bedrock in the west and gentle slopes of boulder clay in the east. The top surface of the dolerite shows grooves cut by stones scraping the surface, these being set in the base of the ice and acting like sandpaper. Other features Corstorphine Hill Tower (also known as Clermiston Tower or the Scott Tower). Situated close to the hill's summit, it was built in 1871 by William Macfie of Clermiston to commemorate the centenary of the birth of Sir Walter Scott. It was gifted to the city in 1932 to mark the centenary of Scott's death. It is a five-storey high tower, on a square plan, with castellation at the top. A walled garden on the hill's western slopes. Originally belonging to Hillwood House, it has been in council ownership since 1927. It had become disused and overgrown, but has now been restored by volunteers from the Friends of Corstorphine Hill. In 2001 and 2004, it was featured on BBC Scotland's The Beechgrove Garden. Corstorphine Hill Cemetery. Situated on Drum Brae, on the western side of the hill, it was established in 1928, and came into council ownership in 1994. The cemetery has 35 graves of Commonwealth servicemen and 165 graves of Polish servicemen from World War II. Barnton Quarry. This former stone quarry closed on 1914. It now contains a three-floor deep underground bunker which was developed in the 1950s as a regional command centre in the event of nuclear war. The site was decommissioned in 1983, after which it was badly vandalised and damaged by fire. Since 2011, volunteers have been refurbishing the bunker