Cairnpapple Hill is a hill with a dominating position in central lowland Scotland with views from coast to coast. Its summit is the highest point in West Lothian. It was used and re-used as a major ritual site over about 4000 years, and in its day would have been comparable to better known sites like the Standing Stones of Stenness. The summit lies 312 m above sea level, and is about 2 miles (3 km) north of Bathgate. In the 19th century the site was completely concealed by trees, then in 1947–1948 excavations by Stuart Piggott found a series of ritual monuments from successive prehistoric periods. In 1998, Gordon Barclay re-interpreted the site for Historic Scotland.
Probably around 2500 BC major henge monuments were constructed with the hilltop being surrounded by a bank outside a ditch about 12 ft (3.5 m) wide cut over 3 ft (1 m) into the rock, with wide entrances from north and south. Inside this an egg-shaped setting of 24 uprights (thought to have been timber posts, or possibly standing stones) enclosed an inner setting of similar uprights.
This cairn was later covered by a second much larger cairn about 50 ft (15 m) across and several yards (metres) high, with a kerb of massive stone slabs, which incorporated Bronze age burial cists, one of which contained a food vessel pot. Subsequently more stone was brought in to increase this cairn to about 100 ft (30 m) diameter, enclosing two cremation burials in inverted urns and now covering the original ditch and bank, making the whole site a tomb monument. Lastly, inside the ditch to the east four graves considered Iron age are now thought to be early Christian because of their east-west alignment, and are dated to around 500 to 1000.
The site is open to the public April to September (check opening times) and has a small visitor centre. The 1940s excavations have been partly covered by a concrete dome replicating the second cairn (although the dome is much higher than the cairn and gives a misleading impression of how the site looked) so that visitors can go inside what was once a solid cairn and see the reconstructed graves, and outside this the surrounding post holes and graves are marked by being filled with colour coded gravel like an archaeological plan, with the red gravel indicating upright pits, and the white gravel denoting the alleged Christian burials.