The Thai people claim to trace their history to a Tai race who emigrated from an area in southern China in waves starting around 1200 years ago, and there is a lot of evidence of their paths of migrations and influences on local cities and the power structure. However, the region was already entrenched with the remnants of longreaching Indian and Sri Lankan states and influence in the ancient Dvaravati culture going back roughly 2000 years, followed by various kingdoms of Mon, Lanna, and Khmer cultures, the latter headquartered in Angkor Wat, and leaving many engineering feats behind upon its collapse.