Cave paintings are paintings that were made on the walls or roofs of caves. Many cave paintings belong to the Palaeolothic Age, and date from about 15,000 to 30,000 years ago. Among the most famous are those in the caves of Altamira in Spain and Lascaux in France. There are about 350 caves in Europe where cave paintings have been found. Usually, animals have been painted, like aurochs, bisons or horses. Why these paintings were done is not known. They are not simply decorations of places where people lived. The caves they were found in usually do not show signs that someone lived in them.