8. Mayan Ruins and Stone Temples
Found Year: 2008 Estimated Value: Unknown
Submerged tunnels were found in an astounding maze of stone pyramids and temples in Mexico in 2008. Some people assume that the Mayans built this network of caves as a tribute to their belief in a voyage through the afterlife accompanied by a dog endowed with night vision.
Mayan Ruins and Stone Temples: @peektravel/Pinterest
They believe that the dead had to overcome dangerous obstacles made of water in order to attain peace, and maybe this cave was the place for that. Even in the absence of ideas about creating gateways to other worlds, the elaborate structures the Mayans built on Earth demonstrated incredible ingenuity. An excellent illustration of those structures is this cave.