That's just a short clip from a BBC series called Planet Earth. There were 5 episodes, with the 4th being on caves. It is a GREAT piece on some interesting caves. It's got some great stuff on Deer Cave in Borneo and some cave diving in Mexico, ending with some good footage in lech. I highly recommend this film.
a quick search on that cave reveals it's 333m deep at it's shortest. That's around 1,000 feet. Amazing. Especially for someone who would basejump into it.
thats sotano de las golondrinas in San Luis Potosi, Mexico.. very famous pit.
for those of you that didnt know about it, you can fit the empire state building in it with room to spare.