The Porvoonjoki river runs through the heart of Porvoo's old town, and the walk along its banks ties together the main sights. From the old bridge near the warehouses you can see the red-painted storehouses to the south and the Cathedral on its ridge to the north. Following the river upstream from the town leads into pleasant parkland that is largely tourist-free.
In summer the river hosts a small boat traffic of kayaks and leisure boats, and several cafes set up terraces facing the water. The best light on the riverfront is in the early morning and late evening, when the colours on the warehouses are at their most saturated and the reflections in the water are undisturbed.