National Astronomical Research Institute of Thailand Thai National Observatory (TNO) is NARIT's main facility, atop Thailand's highest mountain, Doi Inthanon in Doi Inthanon National Park, Chom Thong District, Chiang Mai Province. The concept of a national astronomical research institute was discussed for the first time in the Assembly of the Deans of the Faculty of Science in Thai universities. On July 20, 2004, commemorating His Majesty King Bhumibol's 80th Birthday Anniversary in 2007 and marking the bicentenary of the life and work of King Mongkut the "Father of Thai Science" the government approved the establishment of the National Astronomical Research Institute of Thailand (NARIT), under the
Doi Nang Non southwest of Pong Pha along the border with Myanmar. The mountain range is an unusual land feature when seen from certain angles as its silhouette takes the shape of a reclining woman with long hair. Its highest point is Doi Tung, which corresponds to the belly of the lady. There are a number of caves and underground water courses in the range area. In 1986 an eight km sector of the range which included the entrance to the main cave was declared the Tham Luang–Khun Nam Nang Non Forest Park. On 23 June 2018, a group of twelve boys aged