At this sprawling open-air museum next to Kastelholms Slott, you can stroll around traditional 18th- and 19th-century Ålandic buildings, including windmills and a smoke sauna. The museum shop's guidebook (€2) is invaluable for background on each building.

By the entrance, the small Fängelsemuseet Vita Björn, a jail until 1975, demonstrates how cells and conditions evolved over the two centuries it was in use.