Maeshowe is another one of the Neolithic wonders on Orkney. A vast chambered tomb it stands on an ancient trackway that connects it to the stunningly well-preserved village of Skara Brae, as well as passing near the Standing Stones of Stenness and the Ring of Brodgar.
Various calculations by archaeologists estimate it needed up to 100,000 man-hours to build and complete. Maeshowe is generally described as a tomb, but if so, why does it have a door that can only be closed from the inside? A pivoting stone door blocks off the entrance, but can only be closed from the inside?
Once more the poem The Seer provides a (mythical) answer.