Join us in Denmark's underworld

Visit a top-secret military fortress built to protect Denmark and NATO during the Cold War. Hidden under solid layers of chalk in the cliffs of Stevns Klint, this fortress contains 1.8 km of underground corridors. For 40 years, the fortress was used to spy on the enemy but is now open to the public. Enjoy a guided tour of well-preserved elements of military history 18-metres below ground, and discover hidden views over the Baltic Sea.

Once home to kings and queens, Christiansborg Palace now houses the Danish Parliament. Below this powerhouse, you’ll find ruins of Bishop Absalon’s 12th century castle. Here, King Christian IV’s daughter was imprisoned for over 21 years for the crimes of her husband. The ruins are now open and makes the perfect royal underground adventure. English guiding tours will be available again soon, so be sure to put this on your underground bucket list.

Venture north from Copenhagen to find the Danish Maritime Museum. This submerged building designed by the Bjarke Ingels Group (BIG) was selected as the winner of the 2014 ‘building of the year’ award by ArchDaily. The museum, which resembles a ship, is situated in beautiful maritime surroundings, and has been put into the ground to make sure the view of the closely-situated UNESCO world heritage site Kronborg Castle, 'Home of Hamlet', isn't blocked. 

Once a subterranean water reservoir holding 16 million litres of water, the Cisterns, also known as the only dripstone cave in Denmark, calls for the perfect underground experience for art enthusiasts. The yearly exhibitions promise to be striking and beautiful contemporary art installations that are not to be missed. 

Denmark's Second World War bunkers along the West Coast of Jutland are not underground anymore, but still have an hidden feel to them. Built by the Germans, these bunkers were once right under the sand dunes. Today, the ocean has revealed these elements of military history, and as you take a stroll down the beach, it is like travelling back in time. While you’re at it, go explore the Tirpitz museum - a former gun bunker near Blåvand.

Ready for a little scare and some ‘uhygge’ (that's 'spooky' in Danish!) Take a day trip from Copenhagen to haunted Kronborg Castle, where old spirits roam the corridors. Here in the cellars you can visit Holger Danske, a legendary knight, who now sleeps in the castle’s dungeons, ready to wake up when Denmark needs him next.

Once one of the most powerful Viking cities in Northern Europe, Roskilde holds many secrets. Close to UNESCO world heritage site Roskilde Cathedral, you can sink below the market square 'Stændertorvet' in Roskilde and discover the ruins of medieval St. Lawrence’s Church, which offers a unique glimpse into our medieval past.

Visit the world’s largest limestone mine right here in Denmark. Deep down in the underground of Mønsted, just outside of Viborg, you can explore a large underground system of tunnels and caves and watch bats flitting around in the dark..

Go below the surface at the Citadel (kastellet) in Copenhagen and join the Danish Resistance Movement in the fight against the Germans during the occupation of Denmark (1940-1945). An underground museum, with a bunker-style design, lets you descend into wartime, where you can engage in various types of spying and sabotaging, such as deciphering German war codes, and tapping phone conversations.

We get it… this underground experience may not be one of the spooky ones, but it offers a unique architectural voyage through Copenhagen. Inspired by a Scandinavian minimalist design, the spacious stations and facades are all unique. Visit the 17 underground stations and explore all of Copenhagen’s distinctive neighbourhoods at the same time.