The Burgplatz (Castle Square), formerly the site of the weekly market, is surrounded by important historical evidence of the city´s history. Amongst the items to be found in the late Gothic Salvatorkirche (Church of our Saviour) (1316-1415), which was built on the foundations of a Roman basilica, are the memorial slabs of the universal scholar and cartographer Gerhard Mercator (1512-1594) and the first rector of Duisburg´s historical university, Prof. theol. Johannes Clauberg (1622-1665).

The Mercator memorial in front of the Town hall also recalls Duisburg´s worldfamous citizen.

The Old Market Archaeological Zone containing the 16th century foundations of the market hall, which have been reconstructed since their excavation, are behind the imposing Town hall which dates back to the turn of the 20th century. Text boards, profiles and items uncovered in the excavations give visitors an idea of how the city developed.