Loei, in Isan, is one of the most sparsely populated provinces (changwat) of Thailand. Neighboring provinces are (from east clockwise) Nong Khai, Udon Thani, Nongbua Lamphu, Khon Kaen, Phetchabun, Phitsanulok. In the north it borders Xaignabouli and Vientiane Province of Laos. The city of Loei is surrounded by mountain ranges whose summits are covered by fog and abundant with varied flora. The best known mountains in the province are Phu Kradueng, Phu Luang, and Phu Ruea.