Xieng Khouang Province occupies an area of 15,880 square kilometres and has a total population of 228,882 people (2005 census). It comprises seven districts - Muang Phoukhot, Muang Kham, Muang Nongkhet, Muang Pek, Muang Khoun, Muang Phaxai and Muang Mok Mai. In addition to the majority Lao population (Tai-Kadai/Tay-Thai/South Western Tay-Thai/Lao-Lu), Austro-Thai speakers are represented here by Phuan, Tai Daeng and Tai Dam (Tai-Kadai/Tay-Thai/South Western Tay-Thai/Tai), Tai Nua (Tai-Kadai/Tay-Thai/Northern Tay-Thai) and Hmong and Yao (Hmong-Mien); and Austro-Asiatic speakers by Khmu and O Du (Mon-Khmer/Khmuic) and Muong (Viet-Muong). The province is situated in the north of Laos and is marked by green mountains and karst limestone peaks. Much of the province was heavily bombed during the Việt Nam War and old war scrap is still used for building houses throughout the province. The capital of Xieng Khouang is Phonsavanh. Situated at an altitude of 1,200 metres, it has an excellent climate. Xieng Khouang Province is best known for the Plain of Jars, which comprises thousands of prehistoric stone jars, many of huge, megalithic proportions, located in clusters across the Xieng Khouang Plateau.