The remains of the Castle can be visited
Freudenkoppe Castle

The Freudenkoppe castle ruin, a hilltop castle just one kilometer southeast of Neroth, stands on the Nerother Kopf, a basalt cone in the Vulkaneifel region.
History+
The first documented mention of Freudenkoppe dates back to 1337. Just three years later, in 1340, the complex was completed under John of Luxembourg, then King of Bohemia, as castrum Froudenkube. Its strategic importance lay in securing the northeastern border of the County of Luxembourg, to which Neroth belonged at that time. After the death of John I the Blind, his son and successor, Charles I of Luxembourg (later Emperor Charles IV), transferred the fortress in 1346 to the Elector and Archbishop of Trier, Baldwin of Luxembourg. He used it as a base during the siege of Daun Castle in 1353. After 1440, the castellan Philipp von Sierck, brother of Knight Arnold von Sierck, had the castle house built.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=2041
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: 50.1934, 6.7607