Sayaburi Province occupies an area of 16,389 square kilometres and has a total population of 338,044 people (2005 census). It incorporates 10 districts - Muang Khop, Muang Xianghon, Muang Ngeun, Muang Hongsa, Muang Sayaburi, Muang Muang Phiang, Muang Thongmixay, Muang Paklay, Muang Kenthao and Muang Boten. In addition to the majority Lao population, Austro-Thai speakers are represented here by Lu (Tai-Kadai/Tay-Thai/South Western Tay-Thai/Lao-Lu), Tai Dam and Yuan (Tai-Kadai/Tay-Thai/South Western Tay-Thai/Tai) and Hmong and Yao (Hmong-Mien); and Austro-Asiatic speakers by Htin, Khmu and Mlabri (Mon-Khmer/Khmuic). Though situated quite close to Vientiane, the province is quite mountainous and therefore still relatively remote. The province shares its borders with six Thai provinces. The capital of the province, Sayaburi, is on the banks of the Nam Hung, a tributary of the Mekong. The province houses the Nam Phoun National Biodiversity Conservation Area, which is 1,150 square metres of forested hills that contain Asiatic black bear, dhole, elephant, guar, gibbon, Malayan sun bear and Sumatran rhino. The southern part of the province has many scenic waterfalls, but getting around this part of the province is very difficult.