kaiserswerth, duesseldorf, arches at the ruin of the imperial castle, north rhine-westphalia, germany

ages arches architecture archways barbarossa barbarossas basalt bricks building castle completely day deserted doors doorways duesseldorf emperor europe fortification fortress frederick friedrich german germany historic history imperial kaiserpfalz kaiserswerth lower medieval middle niederrhein north pavement paving rainy rhine rhineland rhinewestphalia rocks ruin ruins stones summer walls were west western westphalia