Ubon Ratchathani, or just 'Ubon' for short, is Thailand's eastern-most province, bordered by Laos to the east and Cambodia to the south. The city was founded, officially, in the late eighteenth century during the reformation of Siam after the sacking of Ayutthaya by the Burmese.
The city doesn't have a lot to offer tourists. There aren't any 'must see' sights in the city itself, and no tourist infrastructure to help you get to some of the interesting places elsewhere in the province. The main draws to Ubon are its annual candle festival held at the beginning of the Buddhist 'lent' period, and as a gateway to Southern Laos. See the map for an overview of the sights there are to see.