In the middle of the town of Bad Vilbel, directly on the banks of the Nidda River, the ruin of a moated castle holds its own. The stone building dates back to the 11th or 12th century and then replaced a homestead, which dates back to the time of the Carolingians. The castle was the seat of the robber baron Bechtram of Vilbel, who drove it so far with its illegitimate and also overpriced customs claims that formed in 1399 an alliance of the disgruntled rulers of Falkenstein and Hanau and the city of Frankfurt and destroyed the festivals. In the 15th century, the archbishop of Trier Werner von Falkenstein rebuilt the castle on the existing stone ring walls.
Since 1987 the Castle Festival Bad Vilbel has been held at the historic Wasserburg from the beginning of June until the beginning of September.
In addition to four of their own theatrical productions, the open-air stage includes numerous guest performances, theater plays for children and matinees (cabaret and solo programs by well-known artists).