17. Lascaux Cave Paintings, France

This site was discovered in France in 1940 when 18-year-old Marcel Ravidat’s dog decided to investigate a hole left by an uprooted tree. He would later return with friends to explore more in depth, thinking it was a secret tunnel to the nearby Lascaux Manor.

Instead, they found cave paintings that date back to the Upper Paleolithic period. It first opened to the public in 1948, but had to close in 1963 as the constant visitation was damaging the paintings. I have to admit, the paintings are actually really impressive. Who knew are long-lost ancient ancestors could paint so well?