The remains of the Castle can be visited
Ulmen Castle

The Ulmen Castle Ruin was a double castle complex consisting of an upper and a lower castle. Its history is linked to the Ulmen Maar and holds the traces of a crusader as well as the legends of robber knighthood.
History+
The origins of the upper castle are presumed to be around the year 1000, with its first documented mention dating back to 1074. From the late 12th to the early 13th century, Knight Heinrich von Ulmen inhabited the castle, bringing back the Limburg Staurothek from the Fourth Crusade. In 1292, the complex was expanded with the addition of the lower castle, situated further down the slope. The 14th century was marked by robber knights who wreaked havoc here. In 1490, Ulmen became an electoral Trier office. Between 1679 and 1689, the castle suffered damage from fires and the troops of Louis XIV, eventually being destroyed. A restoration of the upper castle took place in 1789, but it fell into disrepair again in the 19th century.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=613
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: 50.2085, 6.9815