[1] Na Yung–Nam Som National Park is in the area where Udon Thani, Loei, and Nong Khai Provinces meet.

Anno 2022 it is still a national park in preparation, with an area of 248,259 rai ~ 397 square kilometres (153 sq mi).

Down the valley is mixed deciduous forest, Dalbergia oliveri, Xylia xylocarpa, Pterocarpus macrocarpus, Sindora siamensis, and various species of bamboo such as Gigantochloa albocilliata, Bambusa bambos, Dendrocalamus sp.

Along the nature trail to Yung Thong Waterfall, Pha Daeng is sandstone slope cliff, where a large beautiful lower scenery can be observed.

Next to Pha Daeng, there is a tiny cave that used to be a meditation site for Luang Pu Man Phurithatto.