Burg Maubach, Medieval castle in Kreuzau, Germany.

Burg Maubach, also known as Burg Untermaubach, is an irregular polygonal hill castle built of rubble stone. It stands at 162 metres above sea level above the Rur river in Untermaubach, part of Kreuzau. Its residential tower is a large square ashlar structure with walls two and a half metres thick, forming the western part of the manor house.

Count Adalbert von Nörvenich, who called himself Count of Molbach from 1153, is regarded as the founder; after his death in 1177 the castle passed to his son-in-law William II of Jülich, who moved his residence to Nideggen in 1191. Around 1350 Edmund von Engelsdorf held the castle, and the Gothic residential tower with walls 2.5 metres thick dates from this period. In 1617 the dilapidated complex went to Baron Wilhelm von Efferen, who remodelled it, and after 1717 it received its Baroque form.

The castle reflects building traditions of regional nobility, with thick walls and stone construction that expressed both authority and permanence. Visitors can see how such fortifications served as both homes and defensive structures for their lords.

The fortress is accessible from Kreuzau and sits along walking trails that connect to other nearby places. Wear sturdy footwear, as the paths are hilly and sometimes unpaved.

The residential tower's walls are 2.5 metres thick, and they were deliberately pierced when Wilhelm von Efferen remodelled the castle after 1617, since the medieval defences could no longer withstand gunpowder artillery. He extended the tower eastwards into a manor house, adding living space and comfort.