Central Rønne is comfortably walkable — almost everything in this guide is within 10 minutes of the harbour. To get out and see the rest of the island, BAT runs reliable buses from Rønne to all the main towns (Allinge, Gudhjem, Svaneke, Nexø, Aakirkeby) on a flat fare. Buy a day ticket if you plan more than two trips.
Bornholm is a cyclist's island — there are 235 km of dedicated bike paths, most of them flat and well-signed. Several rental shops sit near the Rønne harbour exit; an electric bike will get you across the island in a couple of hours. A rental car is useful in shoulder seasons when bus frequencies drop.