The Cuween Hill cairn is built, unsurprisingly, into Cuween Hill, outside the village of Finstown, in the Mainland parish of Firth.

The structure lies at the end of a steep trail that climbs up the east-facing slope of the hill.

Although small by Maeshowe’s standards, the Cuween cairn is nonetheless an impressive feat of prehistoric engineering.

Cut into solid bedrock, the cairn comprises a main central chamber with four smaller chambers branching off from each wall.

Access to the interior is by a low, narrow passage, which, being less than one metre high, requires the visitor to get down on their hands and knees and crawl.

Once inside, however, the main chamber is fairly spacious and the visitor can stand comfortably – although in pitch black darkness.

Today, the chamber is over two metres high, but the original roof – which was damaged by 19th century “explorers” breaking into the cairn from above – was probably higher.

Dating from around 3100 BC, the cairn was excavated in 1901.

Back then, the remains – mostly skulls – of at least eight people were found inside. This small number led to the suggestion that, during its use, the chamber was cleared out periodically, with only the most recent, or significant, skulls left.