A chain of small islands in the Oulujoki river, north of the centre, joined by footbridges into a single public park. The botanical gardens, with their two greenhouses (a desert hall and a rainforest hall), are the main draw. Otherwise it's gravel paths, ponds, sculpture, and lawns popular with picnickers in summer and cross-country skiers in winter.
A pleasant 20-minute walk from the market square.