Berlin has a habit of turning its darkest chapters into something worth visiting, and Teufelsberg might be the strangest example yet. The 'Devil's Hill' in the city's west isn't natural at all — it's a man-made mound built from wartime rubble, piled over a Nazi military college too solid to demolish. Today it stands 398 feet above the surrounding Grunewald forest, topped with the ghostly white domes of an American Cold War listening station that has been reborn as one of Europe's most unusual art spaces.

The story is pure Berlin. After the war, plans called for a ski jump on the new hill. The Cold War had other ideas: the US forces built a signals intelligence station there, its satellite dishes and radomes intercepting communications from East Berlin. When the wall came down in 1989, the site briefly handled air traffic control, and in 2007 director David Lynch even tried to buy it as a transcendental meditation centre. That fell through, and for years the complex sat derelict — until artists moved in.

Now hundreds of muralists from around the world have covered the decaying structures in colour. A vengeful winged insect, a snarling tiger, and Uncle Sam riding a speeding bomb all loom out of the concrete, with the once-secretive spy domes as a surreal backdrop. Alongside the open-air gallery there's a small museum honouring the Allied forces who served in Berlin, plus an exhibit digging into the previously top-secret sections of the station that fed American intelligence during the Cold War.

You can explore on your own or join a guided tour — options include a street art tour, a 'myths of Teufelsberg' tour, and a flashlight tour run only in winter. Half the appeal is simply the building itself: your voice echoing inside a tattered dome, or the dark staircase climbing to a panoramic view across Berlin. Entry costs €12 for adults (€10 reduced, €5 for ages 8–17, free under 8), the site is open daily from 11 AM until sunset, and you'll want about an hour and a half to two hours on site. Note the tallest radar tower is only accessible on special guided tours, and closures happen in bad weather.

Getting there is easy: take the S-Bahn to Heerstraße, then walk roughly 30 minutes through the forest to Teufelsseechaussee 10. The best months are April to October on a clear, dry day, when the rooftop views are at their sharpest.

Teufelsberg works for two very different travellers at once — history buffs who want to stand inside a genuine Cold War listening post, and street art fans hunting murals in unexpected places. It's also a short hop from other Grunewald highlights, so it pairs well with a day of lakeside walking in Berlin's greenest district. If your idea of a good afternoon is clambering through a ruined spy station turned graffiti canvas, this should sit near the top of your Berlin list.