The website for Pech Merle offers a virtual visit to one of the most amazing sites of prehistoric cave paintings in the world. Pech Merle is in France and contains many such paintings, including "The Dappled Horses of Pech Merle," approximately 25,000 years old. The website page for one chamber has a 360 degree virtual view.
The cave was discovered by three teenagers in 1922, and its walls are adorned with images of wooly mammoths, other animals, and handprints. Footprints of children, preserved in what used to be clay, were found half a mile underground.
Peche Merle is one of the only sites of prehistoric cave paintings open to the public. And on this website, you can explore it in your chair.
There's a Wikipedia article on Pech Merle, too.
Hat tip: @ChrisStringer65 and @AlisonFisk