Kanchanaburi is both a city and a province in Thailand. For the province, see Kanchanaburi province.Kanchanaburi (thai กาญจนบุรี) is a city in the west of Thailand. Geographical location 14° 2' North, 99° 32' East. Population 52,000. It is located at the river Kwai, where in 1942 the famous Bridge on the River Kwai was built by POW of the Japanese.