The church can be visited
Gandersheim Abbey

The Gandersheim Abbey, a former women's monastery, continues to shape the cityscape of Bad Gandersheim in Lower Saxony. Originally founded as a princely family foundation, it developed into an imperial abbey and housed unmarried daughters of high-ranking noble families for centuries.
History+
The Gandersheim Abbey was founded in 852 by Duke Liudolf of Saxony, the progenitor of the Liudolfing dynasty. For this undertaking, he received papal approval and relics from Pope Sergius II. Initially, the convent was housed in Brunshausen Monastery before the construction of the collegiate church in Gandersheim began in 856. The church was consecrated in 881. As early as 877, the abbey was placed under royal protection, and in 919, it gained imperial immediacy, leading to a close connection with the empire and frequent visits from kings. Until the founding of Quedlinburg Abbey, Gandersheim was the most important Ottonian family foundation and served as a burial site. Around 973, Hrotsvit of Gandersheim, known as the first German poetess, lived here. In the 11th and 12th centuries, the “Great Gandersheim Dispute” arose concerning ecclesiastical jurisdiction, which was only resolved in favor of the abbey by Pope Innocent III in 1206.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Rainer Gindele
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: 51.8704, 10.0261