††††Cave paintings are pictures of people, animals, and contemporary scenes on the interior of a cave, especially by prehistoric people.
Some prehistoric cave paintings are so old that archaeologists can date them by measuring the thickness of layers of stone that have built up on top of the colours. Limestone leached out of the rock by water builds up over the walls of caves covering portions of the paintings. The rate at which the layers build up is known and so the minimum age of the paintings can be calculated. Some of the paintings on cave walls in France and Spain are more than 30,000 years old. The colours were made from natural pigments such as ground-up red and yellow ochre, and applied with brushes made of twigs with chewed ends, animal hair, feathers or pads of fur and moss. Cave paintings provide a picture of life in prehistoric times and of the environment of the people. Pictures in caves in the Sahara desert, for example, show that it was once green and fertile, with abundant wild animals.
