Mariehamn is the capital of Åland, an autonomous, Swedish-speaking province of Finland. It’s also the only city in the world built on an archipelago. The picturesque town is spread out over several small islands connected by bridges, and it’s a great place to wander, explore and enjoy the fresh, Nordic air. Highlights include the ornate wooden houses, the lively harbour and the striking medieval church. Åland is a haven for cyclists, and there are plenty of trails and lanes to explore. Be sure to sample some of the local specialities, such as smoked fish and home-baked bread.