Ubon Ratchathani is one of the four major cities of Isan (with Khorat/Nakhon Ratchasima, Udon Thani, and Khon Kaen), also known as the "big four of Isan." The city is on the Mun River in the southeast of the Isan region of Thailand, and is located 615 km away from Bangkok. It is known as Ubon (อุบลฯ) for short. The name means "royal lotus city". Ubon is the administrative center of Ubon Ratchathani Province.