Aachen Cathedral

The Palatine Chapel of Aachen was built between 792 and 804 by Odon of Metz (742-814). It was Charlemagne's private chapel in Aachen, which was part of his palatine complex. It contains the remains of Charlemagne and was a place of coronation for about 600 years. In the 21st century, the chapel has been preserved almost intact, despite later additions and major repairs in the 19th century. As part of Aachen Cathedral, it is included in the UNESCO World Heritage List.

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.

Built in 1865, the St. Alfons monastery in Aachen, Germany, transformed into an office building in 2008, while preserving its historical features. The conversion process involved reversible modifications and a glass extension.