Uster Castle is a hill castle which was built probably around 1200 AD by the House of Rapperswil in the Swiss municipality of Uster in the Canton of Zürich. Since 1995 it houses a boarding school.
Wikipedia https://en.wikipedia.org/wiki/Uster_Castle
Address 1 Schlossweg, Uster 8610, Switzerland
Coordinates 47°20'43.749" N 8°43'4.441" E