Though this place is much smaller than the Nong Khai aquarium and lacking any Mekong catfish (镁lah b猫uk) on our last visit, it's still mildly enjoyable to see the various species from the Mekong River. It's 6km west of town along Hwy 22.
Admission also includes Chakri Memorial Hall in a nearby building. Most of the displays are about King Rama IX and the province's various ethnic groups, but unless you can read Thai it's probably not worth your time.
厂艔谤苍驳路迟膬补路辞耻 to Na Kae pass in front of the aquarium (20B, 20 minutes).