It's like some kind of pulp adventure tale: deep in the Yucatan jungles, there's a flooded cave complex that the Mayans believed was the entrance to the Afterlife, Xibalba. Scuba divers have, slowly and carefully, explored the caverns and found vast, air-filled chambers filled with temples.
This is right out of Call of Cthulhu -- and I don't mean that in a good way. I mean that in a "Do Not Call Up What You Cannot Put Down" way.
It's cool, yes... but pretty damned creepy. I mean, we're talkin' LifeGems level creepy. The Mayan afterlife is not a happy place; "Xibalba" means "Place of Fear".
We're talking Hell itself, people. They've found Hell. This is not the start of any happy movie; Brendan Fraser wisecracks are the best we can look forward to here.
If I were given to Omens and Revelations....
EDIT: halfelf reminded me that the Mayan calendar ends in 2012!
Okay, now I'm really creeped out.
Found via BoingBoing.
Coincidentally, I spent the morning reading pages at http://www.xibalba.demon.co.uk/ -- also found via BoingBoing.