70. Lascaux Caves, France.
Bird Headed Man with Bison and Rhinoceros.

I've explained this to so many Year 7 History classes. I'd begin by telling the story of Marcel Ravidat, and his friends, out in the woods in the south of France, when his dog, Robot, suddenly disappeared. Then Marcel following the dog's pitiful yelping down a deep hole that unexpectedly widened into a cave, and Marcel lighting a match, the cave actually being one chamber of many, and how hel begin calling up to his friends telling them of the images he was seeing, paintings all over the cave walls, the ceilings, everywhere, and mostly of animals, bison, horses, reindeer, and, as it turns out, this particular wall includes the first ever representation of a human being. It being virtually a stick figure, compared to the fully realized bison where the artist has used the bulges on the cave's walls to suggest a textured depth, then I'd absolutely nail the kiddies' attention by pointing out the bison had just been speared, it's guts hanging out. No one ever asked about the hunter's hardon, if they even noticed, or why the hunter is bird-headed, or what the duck-headed stick might mean, but wondering aloud that if I had no knowledge of this 20,000 year old art work, and been told it was a Picasso, then yes, I can see that. I'd finish this particular lesson with another hypothesis, that perhaps the ability to create art, to see things in the abstract, is a quality that makes us human, differentiating us from every other species on the planet. I taught this so often I began to be in awe of this work, of how perfect it is, and thinking that because Marcel had matches they were probably smokers, so thank God for nicotine.