If you are in the Cologne/Bonn area, the Cologne Cathedral is a must see. Cologne Cathedral (Kölner Dom) is a renowned Gothic masterpiece in Germany, taking 632 years to build (1248–1880). It is Germany's most visited landmark, attracting 6 million people annually, and stands as the world's tallest twin-spired church at 157 meters (515 ft). It is a UNESCO World Heritage site housing the Shrine of the Three Kings.