In the eastern district of Hegi in Winterthur, Schloss Hegi stands as a striking example of a late Gothic manor house in northeastern Switzerland; the estate is registered as a cultural property of national significance. The name goes back to the Zürich German word "Hag", which translates as "fence."
The complex goes back to the lords of Hegi, who appear in documents for the first time in 1225. The castle originally stood on land belonging to the Bistum Konstanz; the family served there as a ministerial lineage and simultaneously held offices and fiefs, among them for Kloster Petershausen, and rights under the Kyburgs and later the Habsburgs. Around the mid-15th century the estate passed by family ties to the Hohenlandenberg, who substantially expanded it under the brothers Ulrich and Hugo. Hugo later became Bishop of Konstanz (1496–1532). In 1519 the lordship passed by marriage to the Aargau family von Hallwyl; the castle developed into the centre of a small territorial lordship. In 1587 the city of Zürich acquired the building and established an Obervogtei there, while the feudal tie to the Bistum Konstanz formally remained in place. After 1798 the castle changed hands several times; in 1915 it came into the possession of a Zurich professor of history. In 1947 the city of Winterthur bought the castle, opened parts of it to the public and used rooms for a youth hostel (1953–2000). Today the house accommodates a museum and is used for cultural events; efforts are being made to cooperate with the Pädagogischen Hochschulen Zürich and Nordostschweiz.
The architectural development can be traced in three phases. The oldest core is formed by a tower with a massive foundation; around 1500 extensive alterations followed, including the three-storey Ritterhaus on the north side, curtain walls and three round corner towers as well as a hexagonal chapel tower at the northeast corner. The complex was once surrounded by a moat fed from a branch of the Eulach; this was filled in during the 18th century. Alterations and additions were carried out in the 17th and 18th centuries; in 1707 the wooden upper storey of the residential tower burned down and was replaced by a masonry storey. Comprehensive restorations were undertaken at the beginning of the 20th century, during which intrusive additions were removed.
The interior includes several historic rooms: a late Gothic room with a vaulted wooden ceiling (c. 1500), the Lower and Upper bailiff’s chambers with paintings, leaded glass windows and heraldic displays, as well as original stove ceramics from the 16th and 17th centuries. The Upper Chapel is polygonal in plan and features an eight-part star vault; its construction is associated with the Hohenlandenberg family.