The land has many mountains. The seat of provincial government, Loei, is in a fertile basin where mountains are all around it. The most famous mountains in the province are Phu Kradueng, Phu Luang, and Phu Ruea. The Loei River, which flows through the province, is a tributary of the Mekong, which creates part of the northern border of the province with neighboring Laos. Phu Thap Buek, the tallest mountain of the Phetchabun Range, is in the province.