The Pentland Hills Regional Park lies 7 miles (11 km) to the southwest of Edinburgh and runs southwest from the A 720 Edinburgh bypass. It is bounded by a line above the valley of the Water of Leith and the A70 road to the northwest, the A702 to the southeast and in the southwest by the boundary of the Scottish Borders Council Area. The park measures approximately 11 miles (18 km) by 6 miles (10 km), with an area of around 10,000 ha (24710 acres). Its highest point is Scald Law at 579m (1900 feet) and the park includes approximately 62 miles (100 km) of paths.
Designated in 1984, the park provides upland pasture for sheep, grouse moor and forestry together with recreational areas (including the artificial ski slope at Hillend, mountain-biking, hill-walking and bird-watching). It also provides the army with training areas and shooting ranges. The park also incorporates several reservoirs important to Edinburgh's water supply; namely Harperrig, Threipmuir, Glencorse, Bonaly and Clubbiedean reservoirs. The area also includes sites of geological interest amongst rocks of Old Red Sandstone and Silurian age.
The Regional Park has its headquarters at Boghall Farm on the A702 Biggar Road. A ranger service provides guided walks, educational visits, in addition to managing the park. The park is supported by Edinburgh, Midlothian and West Lothian Councils, together with Scottish Water and Scottish Natural Heritage.