The Tau Caves, Nadi, Fiji
No, Nadi isn’t going to deliver the longest abseiling in the world but it definitely gets points for uniqueness and thrills. You’ll be dropping straight down into a cave that’s 100 meters deep from a helicopter. Of course, you can always scale down the walls instead, but where’s the fun in that? The entire area around the Tau Caves for some great views and some fun zip line opportunities, too.

http://www.zip-fiji.com/the-caves-at-nadi/