Stock Photo - Tad Xay and Pha Xay (‘Tad’ and ‘Pha’ respectively mean ‘waterfall’ and ‘cliff’) may arguably be the most beautiful ‘twin’ waterfall in Phou Khao Khouay (Laos), particularly during the rainy season.The Houey Xay stream has its source in the northern mountains of the park, meanders through dense and relatively untouched evergreen forest and empties finally into the Nam Mang. By reaching Tad Xay, its crystal clear waters are cascading over seven 1- to 3-meter steps. The water then flows through a picturesque valley for about 800 meters before plunging over another steep 40-meter cliff (Pha Xay). It falls into a breathtaking gorge surrounded by dense forest.