Cisternerne – The Cisterns in Søndermarken

From Lifeline Reservoir to Underground Art World

Cisternerne began life in the mid-19th century, when Copenhagen’s polluted water supply and a deadly cholera outbreak drove the city to create a modern reservoir system. Excavation under Frederiksberg Hill started in 1856, and within just a few years this immense brick cistern was holding up to 16 million liters of clean drinking water beneath Søndermarken’s lawns. For decades it was a crucial hidden infrastructure, quietly stabilising supply and even feeding nearby fountains. By 1933 new water systems had overtaken the old cisterns, and the reservoir was taken out of service. The water remained for decades, a dark, off-limits underworld, until it was fully drained in 1981. In 1996, as part of Copenhagen’s year as European City of Culture, the space opened to the public as an exhibition venue. Later it joined the Frederiksberg Museums and evolved into the contemporary art laboratory it is today.

A Dripstone Cave Beneath the City

Step below the glass pyramid entrance and you enter a space unlike anything else in Denmark. The three long chambers stretch out in semi-darkness, held up by rows of pillars that recall a flooded cathedral. Over time, water seeping through the concrete has created delicate stalactites and stalagmites, making Cisternerne the country’s only true dripstone cave. These mineral formations, simultaneously beautiful and fragile, are a reminder that nature is patiently reclaiming this piece of industrial engineering. The climate is part of the experience. Temperatures hover around 8–10°C year-round, and the humidity is close to 100%. Mist hangs in the air, surfaces glisten, and every footstep echoes off the vaults. Light is sparse and carefully controlled, so your eyes gradually adjust to a world defined by reflections, shadows and the sound of water dripping from the ceiling.

Immersive Art Tailored to the Cavern

Cisternerne hosts one major, site-specific exhibition at a time, typically running from spring to late autumn, with the space closed between shows for reconfiguration. Instead of traditional white-wall galleries, artists here are invited to embrace darkness, moisture and acoustics. Past projects have incorporated shallow pools, boats, mirrored corridors, soundscapes and sculptural light, turning a walk through the cistern into a full-body experience. Because the architecture is so dominant, each exhibition reads as a dialogue between art and place. Works often reference water, memory, geology or the passage of time, amplifying the sense that you are exploring a living organism rather than a static museum. It is common to feel disoriented for a moment, unsure where the artwork ends and the original structure begins.

The Park Above and the Palace Beyond

Above ground, Søndermarken offers a gentle contrast to the subterranean gloom. Lawns, avenues of trees and quiet paths form a green buffer between the cistern entrance and the surrounding city. Just across Roskildevej rises the Baroque silhouette of Frederiksberg Palace, and the nearby Copenhagen Zoo adds to the cluster of attractions in this corner of Frederiksberg. Many visitors choose to combine a visit to Cisternerne with time in the park, using the lawns as a place to decompress after the intense underground atmosphere. On clear days the glass pyramids catch the light, hinting at the hidden volume below without giving away its scale.

Planning Your Visit Inside the Reservoir

Cisternerne is a paid attraction with timed opening hours concentrated in the exhibition season, and it may close temporarily between installations. Inside, the floors can be wet and uneven, and the low light can be challenging, so sturdy, closed shoes and an extra layer are advisable even in summer. The moisture-sensitive environment means you should be prepared for some chill and damp, and photography often requires a steady hand or high sensitivity settings. There is step-free access, although the underground conditions may not suit everyone, and there is no dedicated accessible restroom on site. Mobile reception can be patchy once you descend, adding to the sense of stepping out of everyday life. Give yourself enough time not only to see the artworks but also to simply stand still, listen to the echoes and watch droplets fall through the dimness.