Imperial Castle, Nuremberg, Germany (DE).
Imperial Chapel (Kaiserkapelle) Heathen's Tower (Heidenturm)
The Imperial Chapel (Kaiserkapelle), from an architectural point of view, is the most important building on the castle rock. It was built around 1200, at the same time as the original Palas. It is a romanesque double chapel consisting of two chapels one above the other and connected only through an opening in the ceiling, thus representing the hierarchical levels in the medieval society. -wiki