Cutting and bend

Specus of conduits B (left) and A (right) where they reach the Chaînon de la Pène limestone ridge, looking south. The concrete specus walls of B runs into an excavation that cuts the top of the ridge to reach the Barbegal mill site. Conduit A was originally lined with large limestone blocks, but this was supplemented by a concrete wall. Conduit A does not cut the ridge, but makes a sharp turn to the west