The Norman Switzerland is crossed by the Orne that leaves the Bassin Parisien to enter the Massif Armoricain. Imposing rocky escarpments border it like the Rochers des Parcs south of Clécy. The river begins a bend to the west, then the Rochers de la Cambronnerie straighten its course. There, a railway viaduct, the Viaduct de la Lande or Viaduct of Clécy, was built in 1866 to transport visitors from Caen to Flers. Wide enough for two lanes, it eventually only had one.