Once the castle chapel of the residential castle of the margraves of the Saxon Ostmark, today it is the most prominent witness of Landsberg's medieval history. The former castle chapel belongs to the type of Romanesque double chapels described by Oskar Schürer in his 1929 monograph "Romanische Doppelkapellen". It is one of the largest preserved double chapels and is described as a particularly noble complex. Experts equate it with the imperial double chapels in the castles of Nuremberg and Eger or even place it ahead of them. Both art-historical and regional-historical aspects indicate that the double chapel could not have been built together with the castle around 1170, but at the earliest around 1200 in its present form. Even today, mature ornamental forms and an overwhelming spatial composition testify to the power and prestige of Margrave Konrad von Landsberg (around 1160 - 1210), to whom this building can be attributed.
In modern times, the Landsberg double chapel experiences a varied and diverse use. Informative guided tours on the history of the mountain and the castle by employees of the Landsberg Museum "Bernhard Brühl", which are extended to guided tours several times a year, give the visitor a vivid picture of the former size and importance of the place. The double chapel also provides a charming backdrop for atmospheric concerts and readings.
The Protestant congregation of the Landsberg town church "St. Nicolai" meets monthly from June to September for services in the Romanesque double chapel. Baptisms, confirmations and weddings are also performed by the Landsberg Protestant parish office in the double chapel. The Landsberg registry office also offers wedding ceremonies in the double chapel, in addition to other representative buildings for weddings.