The Cistercian monastery “Kloster Reynevelde” or “Purus Campus” in Latin once stood here between the dam of the Herrenteich, the Hausgraben and the Hellernteichen. Today's streets run through the middle of the former buildings. The monastery was founded in 1186. The monastery church was consecrated in 1236, so the stone buildings were only completed 50 years after it was founded. Previously there was a makeshift wooden structure that is said to have stood south of here on the Klosterberg. As can be seen from the bronze model shown here, the stone monastery was a four-wing complex with the monastery church in the north, which stood on the other side of today's monastery street. The enclosed monastery district stretched from Steinhöferstrasse in the north, where part of the monastery wall still stands, to Hamburger Strasse in the west and the Old Garden in the south to the Herrenteich in the east. The monastery was secularized in 1582 under the Danish King Frederick II and given to the Plön Duke Johann the Elder. J. handed over. He had the buildings demolished by 1599. The demolition material was used to build the ducal castle north of the house moat. The mighty monastery church was initially left standing, but in 1635 the dam of the Herrenteich broke and the monastery church was destroyed.