The town takes its name from its main sight, the 12th-century Romanesque stone church Aa Kirke. Occupying a knoll overlooking the surrounding farmland, this is Bornholm's largest church. Slip inside for a number of historic treasures, including a 13th-century baptismal font of carved sandstone depicting scenes of Christ and featuring runic script. The ornate pulpit and altar date from about 1600.
