Bolnuevo Eroded Formations

The enchanted city of Bolnuevo, in Bolnuevo beach,  is made up of sandy loams or yellowish sandstones, and to a lesser extent of fine lentil-shaped micro-binder. The sandstones have carbonated edges of a bluish-grey color and a different mollusc macrofauna, equinoderms and crustaceans. Sccording to the studies of Francisco Serrano, these rocks have abundant microfossils dating back to the Pliocene (4 million years ago). These rocks, which show different degrees of cohesion, have undergone a differential erosion process affected mostly by water and wind, which has given sandstone strata its honeycomb-like shape.