Kuparivuori is the little climb that makes Naantali make sense. The rocky hill rises just behind the old town, and from the top you can look back over the church, wooden houses, guest harbour, Moominworld island, and the gardens of Kultaranta across the water.
The viewpoint is free and only takes a few minutes to reach, but wear shoes with grip if the rock is wet. It is best at sunset or after dinner, when the day-trippers thin out and the harbour lights begin to come on below.