We've been saving this one for months.
Seventy seven years ago today, four teenage boys Marcel Ravidat, Jacques Marsal, Georges Agnel, and Simon Coencas followed their dog, Robot (seriously ... Robot ... if you can believe Wikipedia) into a narrow cave near Montignac, France and discovered the Lascaux Cave Drawings.
Click on the photo below for just the coolest video/interactive tour of the cave and it's thought to be 17,000 year old drawings.
You can noodle around this fine site in French, English, German, Spanish, or all of the above.
Way super, double highly recommended.