The Grey House is one of the oldest stone houses in Germany. It was the ancestral home of the Greiffenclau family until 1330. Later, employees of Schloss Vollrads were allowed to live in this house. A major fire in 1964 resulted in the historical building being rebuilt. Experts are puzzled about the real age of the Grey House. According to Peter Holstein, it was built around 850. This would make it the oldest stone house in the country. However, Werner Barkbausen dates the masonry to the middle of the 12th century. Finally, when analysing growth rings, Ernst Holstein found that the roof structure was made from oak beams that had been felled between 1035 and 1075. After it had been closed for 25 years, the ‘Wiesbadener Trüffel’ restaurant is located in the Grey House since 2021 – a place where the poor were fed as far back as the 9th century, according to tradition. There is also a café, delicatessen and pub.