Mahasarakham's attractions are an Isan town's: a couple of working temples in the centre, a low-key cultural museum on the university campus, a fresh market that doubles as the town's living room, and a quiet lake or two on the outskirts where students cycle on Sunday afternoons. None of this is going to wrench you off the Chiang Mai-Bangkok-Phuket loop on its own merits — but if you have ended up here for any reason, there is enough to fill a long, slow day.
The best single thing to do in town is to wander between the central market, the Cultural Centre at the downtown MSU campus, and one of the food streets that run alongside the university gates. The most rewarding short trip out is to the Dvaravati-era Phra That Na Dun chedi an hour to the south.