The first structure on the site of Old Bümpliz Castle was a Burgundian royal estate which was built around 900. Around 1250-1270 a round stone tower was built in the center of the site. This round tower was quite unusual for Bernese castles but may indicate a savoyard influence. Since Peter II of Savoy held authority over Bern at the time, it is likely, but not confirmed, that the round tower was built as a symbol of Savoy's power. The round tower no longer exists, but its location is marked with a cross on the floor of the current restaurant terrace. Shortly after the construction of the tower, the wooden wall was replaced with a stone wall and a half-round tower was added to protect the wall. The round central tower was demolished in the following decades. The growing Bernese power began to force Savoy out of Bümpliz and by the late 13th century, there were Bernese nobles who were naming themselves after their estates in Bümpliz. Under the Bernese nobles, the castle remained unchanged until 1470.
In 1470 Bümpliz village and the castle became part of the lands of the powerful Bernese patrician Erlach family. The castle was rebuilt from a purely defensive structure into an impressive administrative and residential castle. A new gatehouse tower was built, and stands, almost unchanged, today. The supports and structure of the drawbridge over the moat are still visible today.
In the following century, the Old Castle became increasingly old fashioned and uncomfortable. In 1742, Daniel Tschiffely hired Albrecht Stürler to replace the old building with the Neues Schloss Bümpliz. The New Castle was built southwest of the Old Castle. During construction, much of the Old Castle was pulled down or rebuilt.
In 1839 Johann Friedrich Albrecht Tribolet bought the Old and New Castles from Carl von Tavel. He rebuilt the buildings and used them as a private sanatorium for mental patients.
In 1979/80 the Castle was rebuilt. The gate was reopened in the gatehouse, a portion of the moat was excavated and a drawbridge added. The windows were rebuilt in the baroque style and the burned roof was rebuilt as close to original as possible. The north-west wing was rebuilt, while the north-east wing was recreated in concrete and glass. A restaurant opened in the north-east wing, the gatehouse and the courtyard. The rest of the building was converted into the Bümpliz village archives and into meeting rooms or offices.
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.