This cave was discovered in 1905 by José Bullón Lobato when he was looking for a peculiar fertiliser for his land, bat droppings. The discovery was of such significance that in 1912 the famous French prehistorian, Abbot Breuil, and others, were called in to study the drawings. The red and black paintings cover a long period: from figurative motifs from the Palaeolithic (20 000 BC) to the very symbolic art of the Neolithic ages (4 000 BC). These limestone formations have more than 2km of galleries of which you can only visit 500m.