The ruins of Balduinseck Castle are about 55 meters long and up to 20 meters wide in an east-west direction. The outer walls of the 18-meter high, four-storey residential tower are well preserved and shape the striking appearance of the ruin. The residential tower has a floor area of 22.7 × 14.4 meters, the walls are up to 2.5 meters thick. A spiral staircase on the left-hand side of the main entrance and nine chimneys have been preserved; they extend over three floors. The fourth floor has no chimneys and was therefore probably used as a storage room and for military purposes. In front of the large main chimney on the ground floor, which is embedded in the east wall, there are still the remains of a well. In addition to the fireplaces, the inlets for wall cabinets as well as the white interior plaster and a white stripe of the former exterior plaster between the third and fourth floors have been preserved.