Schloss Merten is a building belonging to a former Augustine monastery, which was founded by the neighbouring castle. It is likely that the monastery was donated by Countess Mathilde von Sayn and was first mentioned in a document by Otto von Kappenstein and his wife Kunigunde in 1217.
In 1699 the monastery was burned down. It was not until 1791 that the southern wing was rebuilt. The overall site also includes a small neo-Baroque palace, known as the orangery, which the Counts Droste zu Vischering von Nesselrode-Reichenstein had built around 1909 after acquiring the monastery buildings.
The overall site now houses a home for the elderly and a care home.The grounds with the palace garden and the cafeteria in the orangery are open to the general public.
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.