Video: Yab Yum - Searching the Mayan Underworld (Part 3)

Today we have the third, and final, installment of a series of videos we've been sharing all week long that take us into the Yucatan in Mexico in search of some of the world's deepest caves. The series has followed explorer Robbie Schmittner and his team as cave dive into some amazing settings, where they discover remnants of the Mayan civilization that occupied the area centuries ago. In this episode, the crew descends into Yab Yum, a giant sinkhole where they make discoveries that date back to the last ice age.
(Note: If you've missed the first two parts of this excellent series, you'll find them here and here.)