The castle site lies on the territory of Kruft in the county of Mayen-Koblenz in the German state of Rhineland-Palatinate.

Laach was a motte and bailey castle which stood at a height 318 m above NHN} on a rock spur which, at that time, was a peninsula because the level of the lake was 15 metres higher.

It stood above the eastern shore of the lake and was temporarily the seat of the Rhenish counts Palatine.

Laach Castle (Latin: castellum ad lacum) was demolished in 1112 by the stepson and adoptive son of Count Palatine Siegfried of Ballenstedt at the instigation of the abbey, who wanted to be absolutely safe from interference by the lord of the castle, the Count Palatine.

Perhaps the remains of a pagan fort within sight of their monastery caused the monks a certain unease.