Sommerau Castle was built on a rock spur around which the Ruwer river flowed on three sides. In the 13th century the castle was built by the Trier knight family 'von der Brücke', who had their ancestral seat in the Barbarathermen. The castle had fallen into disrepair by the beginning of the 19th century at the latest.
The facility measures 40 x 10 m. In the west, the remains of the former palace or residential building tower up to a height of 10 m, and in the east, the four-storey square keep, which with its four floors also served as a residential tower, is around 16 m high. Apparently an ascending wooden battlement led to a door about 3 m high. To the south on the fourth floor there is a large rectangular door with a toilet bay, the masonry of which is placed on consoles made of red sandstone. The residential building shows, recognizable from the inside, three full floors and half a fourth with the protruding remainder of a chimney that begins on the second floor. Only remnants of the rising masonry can be seen of the surrounding wall that supported the battlements. The remaining transverse walls are in the ground, the ground plan can only be determined through excavations.
Today the ruins are freely accessible.
References:Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.