Loei (Thai: ) Province is located in Thailand's upper North-East. Neighboring provinces are (from east clockwise) Nong Khai, Udon Thani, Nongbua Lamphu, Khon Kaen, Phetchabun, Phitsanulok. In the north it borders Xaignabouli and Vientiane Provinces of Laos. The province is covered with low mountains, while the capital Loei is located in a fertile basin. The Loei River, which flows through the province, is a tributary of the Mekong which, together with the smaller Hueang River, forms the northern boundary of the province with neighboring Laos. Although temperatures in the hot season (April-May) can be more than 40 degrees Celsius, the province is the only one in Thailand where temperatures regularly drops below freezing at night in the cold season (December-January). Loei is rich in national parks, including especially Phu Kradung, Phu Ruea, Phu Suan Sai (also known as Na Haeo) and Phu Luang Wildlife Sanctuary. In 1853 King Mongkut (Rama IV) founded the city of Loei to administer the