The most common tourist activity in the town is to swim or bathe in the river. The water is cold but not intolerably so, and on a hot, humid day there are often dozens of locals and tourists swimming in river or sitting on the rocky shore.
Several places rent out inner-tubes; after renting one, just walk up the dirt track and hop in the river and flow back to town with some rapids on the way. Be careful because immedately after rainfall the river can rise dramatically within seconds.