The transept façades (ca. 1842-1860) were designed afresh by the cathedral architect Ernst Friedrich Zwirner. They are based on the design of the west front and are among the most important works of the Gothic Revival.

Cologne Cathedral, dedicated to St Peter and the Virgin Mary, follows the pattern of the High Gothic cathedrals of northern France. The 4 m high parchment drawing (ca. 1300) of the design of the west façade provided guidelines for the 19th-century builders. There were no such medieval guidelines for the transept façades, which were designed afresh by the cathedral architect Ernst Friedrich Zwirner. For four years, 1880-1884, it was the tallest structure in the world, until the completion of the Washington Monument. It has the second-tallest church spires, only surpassed by the single spire of Ulm Minster, completed 10 years later in 1890. A UNESCO World Heritage Site.