Nice little park in the middle of town.
Cool park, yo
Nice park and has giod playgrounds for kids.
Puolalan puisto has at least two playgrounds. My favorite is the one in the west (close to Turku Park Hotel). It's surrounded by beautiful buildings, no cars are seen or heard. There's both sun and shade and activities especially for toddlers. With bigger kids I'd choose the one next to Taidemuseo.
Both playgrounds have a playgroup from 9 to 12:30 Mon-Fri (puistotäti, which means you can leave your kids there for up to three hours almost for free, but you need to sign up first and you need to be permanently living in Turku). Many of my friends love it (I myself don't live close enough)
Quite small park
Great place for student activities and even for a summer picnic!
Park on a hill in Turku. Nice views. Quite steep so be careful when you get up in the winter.
Nice park to hang out in
Great park. You feel like you are out of the city. Decent views of the river and town. A bit steep if pushing a pram but still doable