Lor Su waterfall in Umphang Wildlife Sanctuary Umphang district of Tak province . Lor Su waterfall that Karen Black is a large limestone waterfall. Located on the height from sea level is 900 meters. River both fell into a steep cliff. The water flows all year round The width of the waterfall about 500 meters of the tiers of a height of 300 meters, surrounded by rainforest. Falls are the sixth largest in Asia.