Aachen — the westernmost city of North Rhine-Westphalia — is one of the most historically important regions in Germany: the place where Emperor Charlemagne (the Christian emperor of the west in the ninth century) built his cathedral. The Aachener Dom, or Aachen cathedral, is one of the oldest in Europe. Charlemagne was buried here in 814, and the cathedral still maintains his throne. It became the first UNESCO World Heritage site in Germany, housing a fascinating mix of Roman and Gothic elements, including enormous colourful stained-glass windows. If that’s not enough reason to visit, Aachen itself is a vibrant, cosmopolitan city with a lovely old town and natural thermal springs where you can bathe.