Genhoes Castle, locally known as Kasteel Genhoes or Oud-Valkenburg, lies west of the village of Schin op Geul, in the Limburg province in the Netherlands.
It is situated within viewing distance of Schaloen Castle.
The castle was first mentioned in 1041. Then it was probably just a fortified tower house. In 1381 it was owned by a Johan van Alden-Valkenborch. Before 1444 it came into the hands of Jan 't Zievel. He left it to his son-in-law Hendrik van Ghoor. It is this Hendrik, or his son Willem, that probably built the present square tower and the west wing. The walls of the tower are around 1.6 meters thick. He also built a gate tower, which has disappeared, at the site of the present gate arch to the bailey. It may be possible that the castle had been destroyed shortly before, during the Burgundian wars under Emperor Maximillian of Austria. Then followed almost 150 years of family disputes and lawsuits which resulted in the assignment of the castle to the King of Spain as Lord of the Southern Netherlands in 1661.
In 1701 the castle was bought by Georg, Baron of Tunderfeld. He was born in Latvia and had served as a general-major in the service of Emperor Leopold I of Austria. In 1749 the castle was again sold, but now to Leonard Thimus, a cloth manufacturer from Aachen. He built the front wing and the arched bridge on medieval foundations thus creating the L-shaped castle we see today. Beneath the entrance was a prison that fell out of use in 1670. His son-in-law Johann Friedrich von Pelser, Lord of Berensberg built the present U-shaped bailey.
In 1814 Oud-Valkenburg was definitely added to the Kingdom of the Netherlands. In 1944 the castle was continuously occupied by retreating German soldiers. The castle is now owned by Natuurmonumenten; an association for nature conservation and environmental protection. They rent the castle out and it is now used as a farm. So, the castle is private property and thus can not be visited.
The castle is moated, as was the bailey in the past.