You can take a short trip like couple hours to the top of Doi Suthep, the sacred mountain in the center of Chaing Mai, there are temple, palace and some restaurants up there.

Back in town, Nimman is good and easy to travel, many cafes and bars to chill the day.

Also there's a street market held in the evening around the old town, the location is depends on the date.

Have a good trip !