Erlach Abbey also known as St. Johannsen Abbey, was founded between 1093 and 1103 by Kuno, Count of Fenis and Bishop of Lausanne, on land that was then an island in the river Thielle. After Kuno's death, the abbey church was completed by his brother, Burchard, bishop of Basel. The new monastery was settled by monks from Saint Blaise Abbey. The Vogtei, initially the property of the Counts of Fenis, passed from them to the Counts of Neuchâtel-Nidau, and from them at the end of the 14th century to the city of Bern, which in took over the domain of Erlach in 1474, definitively acquiring it in 1476.
The abbey was secularised between 1528 and 1529. The nave of the abbey church was demolished, but the choir and transept remained to be used for grain storage. These structures were demolished in 1961 after they had become unsafe, but the choir was rebuilt between 1970 and 1971. The other buildings remained standing, and in the 19th century were put to various industrial uses, until in 1883 the Canton of Bern bought the site back and turned it into a prison. Since 1978, it has served as an adjustment centre for young men.
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.