Canban, there is a lake/pond at some place about a mile from the hotel. Turn right as you walk onto the street. There is a walking path around it and a so-called gym adjoining and I think it was 5 baht per visit. Was never open at any time I strolled around the lake. Took at least 4 turns around to make an hour's walk, including the walk too and from the hotel.
I must concede that there are some nice evening type restaurants in the town. One near the lake also. You really need some local to take you around to find them. There is live music in one big one and the singer guitarist was quite good. Couldnt speak any Angrit/english but could replicate the songs tunefully.