St. Maria ad Gradus is the name of a former church located East of the Cathedral of Cologne, Germany, situated between the cathedral and the Rhine. Founded by Herman II, Archbishop of Cologne, the church was the burial site of blessed Richeza of Lotharingia (died March 1063), a former Queen of Poland and a grandchild of Otto II, Holy Roman Emperor and his wife Theophanu.

https://en.wikipedia.org/wiki/St._Maria_ad_Gradus

St. Maria ad Gradus

Klub Domhof

Fundamente der römischen Stadtmauer im zweiten Keller unter der ehemaligen Sakristei

Römermauer in Schatzkammer

Domsakristei

Künstlerisch ausgeleuchteter Schauraum direkt hinter dem Dionysus-Brunnen an der Straße "Am Domhof"

Baptisterium