Apart from Lake Millstatt itself, the town's main attraction is its Romanesque Benedictine abbey, founded in 1070. This pretty complex consists of a moderately interesting Stiftsmuseum, the attractive 11th-century abbey church, a graveyard, and abbey buildings south of the church with lovely yards and arcades. If you walk downhill along Stiftsgasse from the church, you'll see on the left a 1000-year-old lime tree. The abbey grounds and magnificent arcades and cloisters are free.