Wyher Castle is a moated castle, which lies south of the village center of Ettiswil. It was first mentioned in 1304 as the home of the Freiherr von Wediswil. After passing through several owners, around the end of the 15th century it was acquired by the Feer family. Around 1510, Petermann Feer rebuilt it into a late-Gothic castle. In 1588 it was inherited by Ludwig Pfyffer von Altishofen, whose descendants adopted the name Pfyffer von Wyher. Between 1837 and 1964 it was owned by the Hüsler family, who were local farmers.
In 1964 a fire partially destroyed the castle and it was acquired by the canton. Renovations in 1981–83 and 1992–96 repaired the damage and restored the moat. In 1996 it became a museum, housing the Josef Zihlmann collection of local religious art.
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.