In the Middle Ages, the Nuremberg castle was one of the most important imperial castles of the Holy Roman Empire. The huge complex was built by the Hohenstaufens and their successors over the remains of previous buildings from the time of the Salians. The double Imperial Chapel is one of the oldest remaining parts of the castle complex (c. 1200). Some of the imperial residential and state rooms in the Palas have late medieval and Renaissance panelling. From July 2013 there will be an attractively designed tour through the new presentation of the Palas. Exciting displays, 3D animations on the history of the building, audio guides and guided tours illustrate the eventful history of the Imperial Castle. The Deep Well, which was the castle’s most important source of water in times of siege, is a particularly famous feature. Although the first documented mention of the well dates from the 14th century, it is probably as old as the Imperial Castle itself. The defensive tower in the bailey of the Imperial Castle, the Sinwell Tower, was built in the 13th century and there is a splendid view from the top of the old part of Nuremberg.