The Bua Tong Sticky Waterfall near Chiang Mai is a very unique waterfall to explore. The limestone rocks magically defy gravity as they allow you to actually climb up the waterfall with your bare feet. It's one of those things where you won't believe it till you experience it for yourself.

Also, it's free to visit! Just be sure to watch your step on the slippery spots and grab the ropes if you need them.