Cave of Valdelajo Nature · Sabero, La Montaña de Riaño, León Image of Sabero, not of the place itself. Discovered in 1999, it holds flowstone, stalactites of every size, draperies, columns and aragonite crystallisations in a municipality that coal mining had hollowed out in another way. Photo: David Perez (CC BY 3.0) What to see and do in Sabero