In 1079, during the Investiture Controversy, the castle was attacked and partially destroyed by Abbot Ulrich II of St. Gall.

It is among the largest surviving medieval castle complexes in Switzerland, consisting of a bergfried and palas with additional residential and economic buildings and a chapel, all connected by a ring wall enclosing a large courtyard.

[3] The castle was plundered by the local populace in 1798, but it was again used as an administrative seat from 1803 until 1831, when it was sold by auction to one Franz Heinrich Hirzel of Winterthur who intended to use it as a quarry.

[6] Every summer the Kyburgiade, an international chamber music festival, takes place in the inner courtyard of the castle.

[7] The castle forms an irregular quadrangle with a single courtyard atop a steep hill above the Töss valley.

South of the castle, between the medieval neck ditches, is the French formal garden which was designed in 1700 by Caspar Schwarzenbach.

A walkway goes over the zwinger and connects the palas, or great hall, with the Willenturm (Willen tower) on the north corner of the castle.