The remains of the Castle can be visited
Medvedgrad Castle

The castle ruin of Medvedgrad, whose name means “Bear City,” overlooks the Croatian capital Zagreb. It is a memorial site.
History+
Built in the 13th century, Medvedgrad Castle had numerous owners. Proprietors included King Bela IV, Matthias Corvinus, and the noble families Zrinski and Drašković. Janus Pannonius (Ivan Česmički), a poet and humanist, lived and died here on March 27, 1472. Two earthquakes in 1574 and 1590 led to the destruction and abandonment of the castle. Initial restoration work began in 1973 and was intensified from 1993 onwards.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://en.wikipedia.org/wiki/File:Medvedgrad_1.jpg
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 45.8696, 15.9408