HOFOR: Tunnel under the harbor


Islands Brygge no. 18 and no. 20


Saturday 10-17


  • Hoist / ramp / level access to the front door
  • Level access in the building / site (no stairs)
  • Level access to outdoor areas
  • Lift
  • Accessible restroom
  • Locked doors can be opened from the outside in case of emergency
  • Chairs or benches to rest on
  • Possible to eat / drink
  • Disabled parking
  • Teleloop
  • Member of Solsikkesnoren
  • Member of God adgang

The bridges over Copenhagen Harbor keep city traffic flowing every day. However, during Open House you have a chance to take a shortcut, 25 meters underwater. Discover the tunnel where utility provider HOFOR’s network of pipes brings district heating, water and town gas out to the city.

Underneath the popular Islands Brygge district on the island of Amager, district heating, water and town gas flow in separate pipes out to Copenhagen’s residents. Today, town gas is no longer produced by burning coal, but is instead a mixture of biogas, natural gas and pure air. The underground tunnel is 320 meters long and 25 meters below sea level. And during Open House, you have a chance to explore this underground passage.

Underground Supply Lines

Hovedstadsområdets Forsyningsselskab, or HOFOR for short, is Greater Copenhagen’s utility company, supplying district heating, water and town gas all over the city. A vast network of pipes of all sizes ensures Copenhageners have clean water in their faucets, district heating in their radiators and town gas for their stoves. Take a moment to imagine all these pipes. Now imagine what Copenhagen would look like if all these pipes were above ground. What kind of city would Copenhagen be then?

Cross the Harbor Without Getting Your Feet Wet

Join us on an underwater tour when Open House opens the hatch to this ingenious subsurface system of pipes. You’ll get a chance to cross the harbor – without taking a boat or getting your shoes wet. Take the tour through HOFOR’s underground tunnel from Islands Brygge across the harbor to Kalvebod Brygge and get a closer look at the city’s hidden underwater utility supply.