In addition to rock climbing, this outdoor facility also offers zip-lines, Frisbee golf and self-guided trekking. Call ahead on weekdays to ensure that staff are there. The park is 3km from Chiang Rai, between Tam Tu Pu and the Buddha Cave.
Read more: http://www.lonelyplanet.com/thailand/chiang-rai-province/chiang-rai/activities/extreme-sports/boomerang-adventure-park#ixzz3nE89tDjV