Wat Si Mongkhon Tai is near the immigration checkpoint. The temple houses an important Buddha image of the province, Phra Chao Ong Luang, an image built before the city’s founding. This brick image is 2.2 metres wide and 2 metres high. According to legend, the first lord of Mukdahan discovered it while he was overseeing the city’s construction. In addition, another image made of steel was found under a Bodi tree with only its top part protruding from the ground.