The castle is the town hall of Mersch; for this reason it is not accessible to the public.
As you walk in, the chapel -consecrated in 1717- is on your right. The keep in front of you was built in several construction periods.
The interior of the tower was converted by Paul von der Veltz and Apollonia von Kerpen in the late 16th Century. Fine, ornate fan vaults decorate the ground and first floor ceilings.
The imposing hall of knights which occupies the whole second floor houses a beautiful fireplace featuring the coat of arms of both aforementioned owners while the coats of arms of 16 of their noble ancestors adorn this hall.