Haapaniemi castle was one of the oldest manor houses in Finland, first record of Haapaniemi dates back to year 1469. The castle manor was built probably between 1450-1525 by the powerful nobleman Henrik Klaunpoika Horn, who owned it until 1540s. After Horns Haapaniemi was owned by another famous noble family Fleming.
The castle manor was ruined in the Great Wrath (1713-1721). Fiskars Ironworks bought manor properties in 1737. Today only an arched stone basement remains the manor house. Haapaniemi is nominated as National Built Herigate by National Board of Antiques.
The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.