Video: Take a Dive Into the World's Largest Underwater Cave

Last week I shared the news that the largest underwater cave system in the world had been found in Mexico. Today, we have video footage from within those caves courtesy of National Geographic. As you'll see, this otherworldly place is quite a spectacular submerged landscape. This cave system isn't entirely new however, as it is the actually two previously unconnected caves that were discovered to be linked via a newly found tunnel. Pretty amazing stuff. Check it out below.