The remains of the Castle can be visited
Ilburg Castle

The Ilburg castle ruin stands on a mountain near Ilfeld in Thuringia's Harztor as the remains of a hilltop castle.
History+
Around 1150, Elgerus de Bilstein is said to have built the Ilburg and subsequently called himself Count of Ilfeld. His successor, Adelger von Ilfeld, married Lutrude von Hohnstein around 1162, establishing the comital dynasty of Hohnstein. Around 1180, Elger II moved his main residence to the nearby Hohnstein Castle. The Ilburg lost its importance and was abandoned around 1189. Its stones were later used for the construction of Ilfeld Monastery, also founded by the Counts of Hohnstein.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Roland Neubert, Halle (Saale)
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: 51.5799, 10.7849