Schwanau island in Lake Lauerz is occupied by a ruined castle, a chapel and a restaurant. Traces of occupation on the island date back to around 1200 BC. There is little documentary evidence relating to the castle, but it is believed to have been built at the end of the 12th century and to have been ruined, probably as a result of a fire, as early as the middle of the 13th century.
The island in known to have been occupied by hermits at various times, including the 17th and 18th centuries. In 1684 a chapel was built on the island, but this was destroyed by the tsunami that followed the 1806 Goldau landslide. In 1808 the council of the church in Schwyz sold the island to General Ludwig Auf der Maur on the provision that he rebuild the chapel. The island remained in the possession of the general's descendants until 1967, when it was purchased by the canton of Schwyz. In 2009 it was completely renovated.
References: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.