Thailand is a Southeast Asian country. It's known for tropical beaches, opulent royal palaces, ancient ruins and ornate temples displaying figures of Buddha. In Bangkok, the capital, an ultramodern cityscape rises next to quiet canalside communities and the iconic temples of Wat Arun, Wat Pho and the Emerald Buddha Temple (Wat Phra Kaew). Nearby beach resorts include bustling Pattaya and fashionable Hua Hin. There is evidence of human habitation in Thailand that has been dated at 40,000 years before the present, with stone artifacts dated to this period. Thailand in its earliest days was under the rule of the Khmer Empire, which had strong Hindu roots, and the influence among Thais remains even today. Since the political reform of the absolute monarchy in 1932, Thailand has had 19 constitutions and charters. Thailand comprises several distinct geographic regions, the north of the country is the mountainous area of the Thai highlands. The northeast, Isan, consists of the Khorat Plateau, bordered to the east by the Mekong River. The centre of the country is dominated by the predominantly flat Chao Phraya river valley, which runs into the Gulf of Thailand. Southern Thailand consists of the narrow Kra Isthmus that widens into the Malay Peninsula. Thailand's climate is influenced by monsoon winds (the southwest and northeast monsoon). The southwest monsoon, which starts from May until October brings warm, moist air from the Indian Ocean to Thailand, causing abundant rain over most of the country. The northeast monsoon, starting from October until February brings cold and dry air from China over most of Thailand. Asian tourists primarily visit Thailand for Bangkok and the historical, natural, and cultural sights in its vicinity. Western tourists not only visit Bangkok and surroundings, but in addition many travel to the southern beaches and islands.