The Cisterns are located under Frederiksberg Hill in the heart of Søndermarken Park, The Cisterns is the only dripstone cave in Denmark. The natural formation of stalactites and stalagmites are not uncommon for concrete structures, yet none anywhere can offer the sheer magnitude and diversity of those found here.
MORE INFORMATION ON THE CISTERNS
Link to the official page with opening hours etc. http://www.cisternerne.dk