The houses in the Düsterngraben were close to the wall, so that little light reached the houses. A good explanation why this street was so designated.Aron Hirsch & Co. had in the Abtshof the administration building of the metal trade. Production was in Ilsenburg and Eberswalde. DasSchwab writes:On the [...] descending steps [...] I descend to the Düsterngraben, one side of which forms the former castle wall, on which rise the houses and gardens of Domplatz. The moss proliferates on the mighty weathered stones.On Petershof writes Schwab:The neighbor of the Liebfrauenkirche, the Petershof, originally built by Burchard I in the middle of the eleventh century, is with the exception of the still preserved foundations of the northern wing probably the work of later centuries.The portal of the western wing bears the date 1552 and forms the entrance to a staircase house lit by slanted windows, which leads to the rooms of the district court.The once proud residence has long since been stripped of its dignity, and the gray of everyday life now descends upon the site of former greatness; but when a poet's eye wanders over the walls, they rise again in ancient glory.In 1916, Petershof is home to the district court. Today it houses large parts of the city administration and the Heinrich Heine Library.