I visited the Lascaux caves in France when I was a teenager. I saw the engraved images but sadly the part of the caves with the paintings was closed to the public for conservation reasons, which I understand. I was disappointed at the time though. However, now thanks to the internet you can visit the caves virtually. Check this out, it really is fantastic: http://www.lascaux.culture.fr/

(via Lascaux Caves, France)