
1) Chambered cairn in Scotland
Found on
https://www.crosswordclues.com/clue/maeshowe

Maeshowe (or Maes Howe; Norse: Orkhaugr) is a Neolithic chambered cairn and passage grave situated on Mainland, Orkney, Scotland. It was probably built in around 2800 BC. It gives its name to the Maeshowe type of chambered cairn, which is limited to Orkney. Maeshowe is a significant example of Neolithic craftsmanship and is, in the words of the ar...
Found on
http://en.wikipedia.org/wiki/Maeshowe

Maeshowe is an artificial mound in the Orkney Islands, on Mainland, nine miles west of Kirkwall. The mound contains an interior chamber, 15 feet square, having a height of 13 feet. Leading to this is a long, low, and narrow passage. The structure was probably sepulchral, but both the reason and date of its origin have been disputed.
Found on
http://www.probertencyclopaedia.com/browse/AM.HTM
No exact match found.