In the early and high Middle Ages, Regensburg was one of the most important trade centres in the south-east of Germany and, accordingly, boasts a wealth of historically valuable edifices. This holds true, too of the buildings embracing Haidplatz, Rathausplatz and Kohlenmarkt. Any efforts at revitalizing the Old as well as respecting and preserving the original town planning interrelations, and last not least the original materials used e. g. for pavements, had to take into account this historical heritage.