The oldest European cave art dates back 40,800, and can be found in the El Castillo Cave in Spain. Other cave painting sites include Lascaux, Cave of Altamira, Grotte de Cussac, Pech Merle, Cave of Niaux, Chauvet Cave, Font-de-Gaume, Creswell Crags, Nottinghamshire, England, (Cave etchings and bas-reliefs discovered in 2003), Coliboaia cave from Romania (considered the oldest cave painting in central Europe) and Magura, Belogradchik, Bulgaria. Rock painting was also performed on cliff faces, but fewer of those have survived because of erosion. One well-known example is the rock paintings of Astuvansalmi in the Saimaa area of Finland. When Marcelino Sanz de Sautuola first encountered the Magdalenian paintings of the Altamira cave, Cantabria, Spain in 1879, the academics of the time considered them hoaxes. Recent reappraisals and numerous additional discoveries have since demonstrated their authenticity, while at the same time stimulating interest in the artistry of Upper Palaeolithic peoples. Cave paintings, undertaken with only the most rudimentary tools, can also furnish valuable insight into the culture and beliefs of that era.