They started probably long before us…

"Before homo-sapiens"? Does this kind of thing not prove the opposite?

Amazing. There is so much buried mystery in Europe

Y’a Quand meme des villes entières qui ont été ensevellies au fil des ans... et si ces cavernes n'étaient pas si souterraines autrefois?

and still blink of an eye relative to the history of Earth itself, there's so much left to know out there