Barnenez
The Cairn of Barnenez (also: Barnenez Tumulus, Barnenez Mound etc.; in Breton Karn Barnenez; in French: Cairn de Barnenez or Tumulus de Barnenez) is a Neolithic monument located near Plouezoc'h, on the Kernéléhen peninsula in northern Finistère, Brittany (France). It dates to the early Neolithic, about 4500 BC; it is considered one of the earliest megalithic monuments in Europe. It is also remarkable for the presence of megalithic art.
Read more about Barnenez: Comparable Monuments, Exhibition, Bibliography