aachen aix-la-chapelle angle architecture barbarossa barbarossa's barbarossaleuchter below bottom building buildings cathedral cathedrals ceiling ceilings chandelier chandeliers christian christianity church churches cultural cupola cupolas decorated design deutschland dome embellished europe from germany heritage imperial indoor indoors inside interest interior low low-angle monument monuments nobody nordrhein-westfalen north of ornament ornamentation ornamentations ornaments ornate photography place religion religions religious renaissance rhine-westphalia sight sights site sites travel unesco view world