Risør's old town grew rich on timber and shipping in the 18th and 19th centuries, and the shipowners and captains who made that money built close together around the harbour, packing tall white wooden houses along lanes too narrow for a car to pass. Almost none of it has been rebuilt or prettified for tourists — it's simply the town as it's always been, which is why it's often held up as the best-preserved example of this style on the whole coast.
There's no set route: the pleasure is in wandering the lanes, finding a bench by the water, and watching the harbour go about its business.