The remains of the Castle can be visited
Peperburg Castle (Ruin) (Grevenbrück)

The Peperburg ruin, a former hilltop castle, is located above Grevenbrück in the Olpe district, North Rhine-Westphalia. It was the original ancestral seat of the noble lords of Gevore.
History+
Peperburg was used from the first half of the 12th century and remained inhabited until the late 13th century, even after the lords of Gevore moved to Bilstein. In the 19th century, most of the complex was destroyed by quarrying, so today only the foundation walls of the southern part of the castle remain. Archaeological findings show that the castle underwent at least four construction phases and was destroyed and rebuilt several times. In 1354, the castle was refortified by Count Gottfried IV of Arnsberg, but was destroyed again in 1355 by Count Engelbert III of the Mark. The family of the lords of Pepersack, who were enfeoffed with the castle, became increasingly impoverished and sold their possessions. In 1432, the heiress Alheid von Hundemen gen.
Source: Wikipedia · Licence: CC BY-SA 4.0
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: 51.1433, 8.0111