Soi Sawan Waterfall Pha Taem National Park is formed by streams flowing together looking like a necklace. There are colorful flowers blooming beautifully.This famous rock formation is located within Pha Taem National Park in Ubon Ratchathani Province. It's situated in the same area as the Pha Taem National Park Ranger Station No. 1 (Soi Sawan) and not far from Saeng Chan and Na Pho. The rock is large standing 30 meters tall and was formed by the confluence of the Soi and Sae Phai streams flowing from two sides to create a necklace-like shape before flowing into the Mekong River. This is the origin of the name Soi Sawan (meaning "necklace of heaven").