"A team of archaeologists is currently conducting excavation work on 20 hectares of land in Fleury-sur-Orne (northwestern France), which is earmarked for residential development. This site has revealed an important Middle Neolithic (4500 BC) necropolis containing twenty monuments and some intact burials." Source: Past Horizons.
"During the Middle Neolithic new types of monuments appear: constructions of earth and wood, varying in length from a few dozen to several hundred metres. These monumental tombs, the first of their kind are called "Passy" – named after the eponymous site found in Yonne (Burgundy)."