Ive never come across this before, its a unique, fun and cheap thing to do during your visit to La Paz. You dont need to book, you just turn up. You have the choice of a standard orange suit or a fun but slightly stinky fancy dress suit (batman, catwoman, santa, spiderman, captain america & superman). The training is very good, you get to practise on a mini wall in the office first. There were 4 guides helping us when we rappelled down face first. They are all very nice and make u feel at ease. All was going well until i lost my footing half way down. One thing they had neglected to tell us is what to do if you lose your balance/footing. I was flailing around for a good 5 mins, bouncing off the wall, trying to stand back up on the wall. I couldnt hear the guy below or the girl above and didnt know what to do. Finally they got the megaphone and started shouting instructions at me. It would have been nice if they had told us what to do in this situation beforehand or explained that its actually quite hard to walk all the way down and that its normal/easier to jump/bounce down it once youve got going. Im not easily scared but i was a little freaked out when i was dangling helplessly. All 3 other people who went down were fine, no one lost their balance except me. Im clearly not a natural and although i was slightly freaked out i would do it again now i know how it works.