The scale of Cologne Cathedral is evident from its two mighty towers. Completed in 1880, they dominate both the city and the surrounding region. At the time of its completion in the 19th century, the cathedral was the biggest building in the world. The design of the west side was truly groundbreaking. It has the largest exterior surface of any church in the world, said to be around 7,000 square metres, and is flanked by two huge towers, each rising to a height of 157 metres. The cathedral houses a wealth of important art treasures, including colourful stained glass windows that bathe the church interior in a mysterious light; the Ottonian Gero Cross (around 980 AD), the oldest large-scale sculpture in the western world; the shrine housing the relics of the Three Kings (1190-1225), an outstanding example of Rhenish goldwork; the altar of the patron saints of Cologne by Stefan Lochner (around 1450), a masterpiece of the Cologne school.
