Tholos do Barro
Santa Maria, São Pedro e Matacães, Portugal
The Tholos do Barro (also known as the Tholos da Pena) was a Chalcolithic or Copper-Age domed tomb of block masonry. Its ruins are located on Monte da Pena, near the village of Barro, Torres Vedras municipality, in the Lisbon District of Portugal. The tholos was classified as a National Monument in September 1940.
Archaeological site data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).