The Abbey can be visited
Amelungsborn Abbey

Amelungsborn Abbey, a former Cistercian monastery and now an Evangelical one, is situated on the southern edge of the Odfeld in southern Lower Saxony. It is considered the oldest Cistercian foundation in this region after Walkenried Abbey. The abbey church of St. Marien also serves as the parish church for the surrounding villages of Negenborn and Holenberg.
History+
The foundation of Amelungsborn Abbey occurred between 1123 and 1135. Monks from the Cistercian monastery of Altenkamp in the Lower Rhine region settled on the land donated by Count Siegfried IV of Northeim-Boyneburg and Homburg. The monastery's name derives from a spring within the abbey grounds, the 'Born' (well) of Amelung. The consecration of the monastery took place in 1135 by Bishop Bernhard I of Hildesheim. The abbey developed successfully economically and founded daughter monasteries, including Mariental (1138), Riddagshausen (1145), and Doberan (1171/1176).
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: https://en.wikipedia.org/wiki/File:Kloster_Amelungsborn.jpg
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 51.8972, 9.5931