Barnenez Cairn in France - Oldest Building in the World
The Cairn of Barnenez is a Neolithic monument located near Plouezoc'h, on the Kernelehen peninsula in northern Finistere, Brittany (France). It dates to the early Neolithic, about 4800 BC; it is considered one of the earliest megalithic monuments in Europe. It is also remarkable for the presence of megalithic art.
Radiocarbon dates indicate that the first phase of the monument was erected between 4850 and 4250 BC, and the second phase between 4450 and 4000 BC. Sources
Tumulus of Bougon
The Tumulus of Bougon or Necropolis of Bougon is a group of five Neolithic barrows located in Bougon near La-Mothe-Saint-Heray, between Exoudon and Pamproux in Poitou-Charentes, France. Their discovery in 1840 raised great scientific interest.
To protect the monuments, the site was acquired by the department of Deux-Sevres in 1873. Excavations resumed in the late 1960s. The oldest structures of this prehistoric monument date to 4800 BC. Sources