Cologne Cathedral is a Catholic Cathedral located in the heart of Cologne, Germany. The building is well known for its Gothic architecture and two spire towers. Construction began mid-13th century and was not completed until the late 19th century. Visitors can find the Shrine of the Three Kings inside the cathedral, the Gero Crucifix, and various stained glass windows such as Petrus- und Wurzel Jesse-Fenster, 1509, to the modern stained glass window by Gerhard Richter.