Canyoning is simply making your way down a river canyon any way possible: sliding among slippery cobblestones mid-river, rappelling, and sliding or jumping down waterfalls. You drive first to a jumping-off point upstream, and then carry ropes and gear to water's edge before slipping on wetsuits (the water is plenty cold up here in the Andes).
Following an experienced guide, you do things that any sane person would never consider - and have the time of your life! One member of our group dangled upside down in a waterfall for a minute while trying to dislodge her foot from a crevasse.
The entire experience takes about 4 hours, and for us, was topped off with a delicious meal at Arassari Trek's office/restaurant.
This experience is only for the adventurous in fairly good physical condition, having the attitude that, "This looks totally dangerous, but they do it every day, so I'll probably survive too."
It’s about the best way to spend $50. We were sore at the bottom, but would eagerly do it again and again.