sentences:  The chambers of these monuments cannot have been roofed with capstones (the uprights are too small to have supported capstones large enough to span the chambers), and corbelled vaulting would be impractical given the character of the available stone.It is conceivable that these chambers had wooden roofs, but recent excavations at La Hougue des Géonnais  provided no evidence for this.Assuming that the chambers were open, the cairns of these monuments cannot have covered the chambers whilst they were in use, and must rather have formed a sort of platform around an open ‘arena’.”
  
  A large flat granite slab at the western end of The Railway Walk where it meets La Rue de la Corbière.