Interior of Aachen Cathedral (Aachener Dom) in Aachen, Germany. Built as Charlemagne’s royal chapel, it is one of Europe’s oldest cathedrals and a UNESCO World Heritage Site, renowned for its architecture and historical significance.

Interior of Aachen Cathedral (Aachener Dom) in Aachen, Germany. Built as Charlemagne’s royal chapel, it is one of Europe’s oldest cathedrals and a UNESCO World Heritage Site, renowned for its architecture and historical significance.

View of Aachen Cathedral (Aachener Dom) in Aachen, Germany. Built as Charlemagne’s royal chapel, it is one of Europe’s oldest cathedrals and a UNESCO World Heritage Site, renowned for its architecture and historical significance.

Detail of Aachen Cathedral (Aachener Dom) in Aachen, Germany. Built as Charlemagne’s royal chapel, it is one of Europe’s oldest cathedrals and a UNESCO World Heritage Site, renowned for its architecture and historical significance.

Recreation in a park, Aachener Weiher, pond, in the summer, Belgian quarter, Cologne, North Rhine-Westphalia, Germany, Europe