The Blanches Pierrs, or Blanches Banques, are composed of the several monuments: The Ossuary, a chalcolithic cist grave dated from the 3rd millennium BCE; three menhirs known as the Broken Menhir, the Little Menhir and the Great Menhir whose function remains unclear (ritual stones or boundary markers?), and La Tête des Quennevais, a ritual complex from the 3rd millennium BCE discovered in 1986 and overlooking the Ossuary.
The prehistoric land surface has been dated from the Neolithic and Chalcolithic period, but other finds testify human occupations until the Bronze Age and Gallo Roman period and even the Medieval times.
