The Aachen Cathedral, built on the former Palatine Chapel of the Palace of Charlemagne (800-814), is the most important architectural example of the Carolingian Renaissance. The Aachen Cathedral is a heterogeneous structure, influenced by many stylistic epochs, characterized by numerous breaks and extensions. To symbolically anchor their reign in the wake of that of Charlemagne, a large portion of the rulers of the Holy Roman Empire, between 936 and 1531, were crowned here.
St. Michael's Church was built in 1628 as the monastery church of the Jesuit community in Aachen. With the abolition of the Jesuit order in September 1773, the church was closed and during the French period, it was converted into a grain store. In 1804 it became a Catholic parish church. In 1987, the church was acquired by the Greek Orthodox parish of St. Dimitrios.
The Trinity Church, built between 1897 and 1899, is the largest Protestant church in Aachen. During the Second World War, the church was severely damaged and the building remained empty for several years. In 1948, restoration work was finally undertaken, and the church was put back into use in 1955. Abandoned as a parish church since 2006, it is now used for religious events with young people (Jugendkirche).