The high point of the Koblenz Altstadt — a twelfth-century Romanesque basilica with a Gothic choir and a pair of twin onion-domed Baroque towers. Built on the foundations of a Roman temple and then a Carolingian church, the building has been rebuilt and reskinned every two or three centuries since.
Inside, the architectural patchwork is the main interest: a Romanesque nave, a Gothic vault, a Baroque chancel, and a series of 1950s stained-glass windows replacing those lost in 1944. Free to enter, almost always quiet, and the towers are visible from anywhere in the centre.