Cisternerne

Beneath the Sondermarken park lies a reservoir built in the 1850s to supply Copenhagen with drinking water, drained in 1981 and reopened as an exhibition space in 1996. It is a vaulted hall of some four thousand square metres held up by rows of columns, with no natural light, a temperature that hovers around eight degrees, humidity near saturation and water dripping constantly from the roof, where stalactites have begun to form. One large installation is commissioned each year and artists work with the conditions rather than against them, using water, sound, darkness and reflection, so the space itself is always the main material. Two glass pyramids in the park lawn above are the only sign of it from the surface.

What you actually see

• A vaulted underground reservoir - four thousand square metres of columns.
• Forming stalactites - mineral growth on the roof since the water left.
• One commissioned installation a year - work made for these conditions.
• The glass pyramids above - the only surface trace, in the park lawn.

When to go

March to November for the main exhibition season; hours are reduced in winter and it sometimes closes between installations. One to two hours. Book ahead for popular shows, which sell timed slots.

Honest expectations

It is cold, dark and wet: bring a coat whatever the weather above ground, and expect drips. Floors are uneven and slippery, and accessibility is limited. There is one installation, so if it does not appeal there is nothing else to see. Closed between exhibitions.

Nearby

Frederiksberg Gardens and the zoo are next door; the park itself is free.