The Aachen Cathedral is one of the most ancient cathedrals in Germany and one of the most important historical establishments of the country.
Founded at the beginning of the 9th century by the famous German Emperor, Charlemagne, who is actually buried inside the Aachen Cathedral. During the following years, the cathedral witnessed the crowning of various rulers of the country.
Germany. There is for example the Shrine of Charlemagne, many mosaics, in addition to the magnificent architecture and decoration of the cathedral.
Germany link: https://www.righttravel.info/country/germany-18.html