I-san is noted for being the center of age-old civilization and customs dating back to pre-historic time and to the period when the Khmer people help sway in the region. Relics and monuments still stand, attesting to the splendors and majesty of the ancient era. The Pha That Phanom in Nakhon Phanom, the Prasat Hin Khao Phanom Rung in Buri Ram and the Prasat Hin Phimai in Khorat, are some of the most important and interesting structures in the area. The Ban Chiang village in Udon Thani, where remains of pre-historic skeletons and tools have been discovered, serves as a most concrete evidence of a Bronze Age civilization flourishing 5,000 to 7,000 years ago [Visit Thailand Guidebook]