Nong Khai is a province in the upper northeastern region of Thailand. It borders the provinces of Bueng Kan, Sakon Nakhon, Udon Thani, and Loei, and also shares a border with Vientiane and Bolikhamxai Province in Laos. Nong Khai is narrow but long in size and is renowned for its culture and tourism, especially for the viewing of the Naga fireballs during the End of Buddhist Lent festival.