The steep rocks are perfect for rock climbing. There are paths around the canyon for hiking/walking, both along the river and up into the hills where you can enjoy the beatiful view of the canyon. You can't fully appreciate it until you have seen it from above. The river is also suitable for kayaking, or so I've been told.
Equipment: If you plan to go free climbing, it's best to have your own gear (as always), but if you get in touch with climbers from the Matka club, I'm sure they will help with advice or anything else you may need.
Just after the dam of Lake Matka, there is a course for kayaking.
The water gets pretty wild!