Basilika St. Aposteln (Basilica of the Holy Apostles), Cologne

Basilika Saint Aposteln (Basilica of the Holy Apostles) is a magnificent Romanesque church. It was constructed during the 11th century and is one of the twelve Romanesque churches built in Cologne during that time. The church has a basilical plan of nave and aisles, and like Groß Saint Martin and Saint Maria im Kapitol, has three apses at the east end making a trefoil plan.

One of the main features of the church is the domed clover leaf chancel, which was built around 1200 and is a true gem of Romanesque architecture. The chancel is located at the east end of the church, and its shape is reminiscent of a clover leaf, with three semicircular apses arranged in a trefoil plan. The chancel is covered by a stunning dome that gives the church a monumental and almost Byzantine appearance.

The church was significantly enlarged in the 13th century, and an octagonal dome was added above the crossing. This new addition further enhanced the grandeur of the church, and it is now one of the most remarkable examples of Romanesque architecture in Germany. Despite the building modifications, the old structures were retained and copied, and integrated into the new construction project.