I recently watched the James Cameron movie ‘Sanctum’. The movie was incredibly boring but I was impressed by the cave(s) they used to film the movie. When I got home I Googled it and as it turns out the cave in Sanctum is based on a cave in Mexico called the cave of swallows and a lesser known cave in Papua New Guinea called Nare. They are both very impressive caves especially the cave of swallows, which Im going to talk about in this article.
The cave of swallows is a pit cave, with a diameter of about 60 meters at the rim and a straight vertical drop off of over 333 meters (1094 feet) – it is an incredible site!
I have included a cross section of the cave and as you can see the cave is massive, in fact it is large enough to engulf the empire state building.
The cave of swallows is truly massive (the largest cave shaft on Earth) and its shear size attracts extreme sport enthusiasts from around the world including climbers, rappellers and base jumpers. To rappel to the bottom of the cave takes approximately 20 minutes and climbing back out again takes around an hour of straight vertical rope climbing (very difficult stuff). I saw a video on TV not long ago of someone base jumping down the cave. I checked it out and it takes around 10 seconds to free fall from the mouth to the floor with a parachute. You can check out some great videos on youtube of people base jumping into the cave. What a rush that would be diving deep underground at high speed into a massive and pitch dark cave with nothing put a parachute to slow you down!
So what about the bottom of the cave?.. Well lets just say its no spot for a picnic, cold, dark and infested by scorpions, millipedes and snakes. The cave is also home to a variety of bird species (who live on the sides of the cave shaft) including swifts and parrots. At the very base of the cave there is a narrow sinkhole in a fault of limestone that goes down at least another 512 meters. So this cave goes down a lot deeper than just the bottom of the main pit. I tried finding details about exploratory missions inside the cave, aside from the usual base jumping expeditions the details are scarce but it turns out the cave wasn’t even explored by modern people until just two and a half years before man walked on the moon; Dec 27, 1966 by T. R. Evans, Charles Borland and Randy Sterns. The tunnels below the main pit stretch for miles with many totally unexplored passages but these passages require respirators to navigate safely.
It turns out there actually are a few unexplored frontiers left on Earth and caves and the underground happen to be one of them.