Inside the vast and impressive Midhowe Cairn on the island of Rousay in Orkney. 23m long internally and 32.5m long externally and with 12 compartments or stalls, it is thought to have been built in around 3500BC. More pics and info: https://www.undiscoveredscotland.co.uk/rousay/midhowecairn/index.html





