Valley of the Big Stones, Terrigenous sedimentary rocks, polygenic conglomerate. If Pietra Cappa dominates, fascinating and intriguing among the thousands of legends attributed to it, the extensive formation of the Calabrian-Peloritan Arc to which it belongs is not less important. The Valley of the Big Stones, also defined as a geosite of international relevance, is situated in the territory of two Municipalities of the Locride area, San Luca and Careri.
It belongs to the Stilo-Capo d’Orlando Formation which is extended to the Peloritani mountains in Sicily and remains geologically included between the tectonic units of the crystalline base and the varicolored clays. It is an area steeped in humanity and spirituality, where the way of anthropising of local people and visitors has always seemed to be marked by the silence and sanctity this sort of geological sanctuary induces to. It seems to be difficult to date exactly back to the settlement works in the area. The probable period of time seems to be between the seventh and ninth century AD. when a real migration of Basilian monks, fleeing the persecutions ordered by Emperor Leo III Isauric, took place. They went to Puglia, Calabria and Sicily in search of places to work and pray in solitude, left surprising places such as the Rocche di San Pietro or Pietra Castello to posterity.