Almost all tours beneath the city are run by Berliner Unterwelten e.V., an association that uncovered many of these sites itself. The sites are not accessible, you walk or stand most of the time, there are steep stairs and no toilets on site. Children under 7 cannot take part, and some tours have higher age limits.

The tours

01 Dark Worlds · Gesundbrunnen

about 4 minutes from Gesundbrunnen U-Bahn station to the meeting point

Directions in Google Maps · Official site

Behind a green door in Gesundbrunnen U-Bahn station, Second World War shelters spread over several floors. After the war they were not blown up because that would have endangered the U-Bahn tunnel, and in 1998 the association rediscovered them. Today they house the Berliner Unterwelten Museum with finds from bunkers of the old government quarter, and the tour also explains pneumatic post, brewery cellars and sewers. The meeting point is Brunnenstraße 105 at the southern entrance to the U-Bahn station. Recommended from year 8 at the earliest.

02 From flak tower to rubble mountain · Humboldthain

about 8 minutes from Gesundbrunnen U-Bahn station into Volkspark Humboldthain

Directions in Google Maps · Official site

Between 1940 and 1942 Berlin built three pairs of flak towers, one of them in Humboldthain: bunkers of about 70 by 70 metres and around 40 metres high. After the war the Allies blew them up; the north side in Humboldthain only survived because the railway tracks next to it must not be damaged. By 1950 around 1.4 million cubic metres of rubble had been dumped on top. Since 2004 the association has led tours through three of the seven floors, with helmets and views from bridges into the depths. Participants must be 18 or older, and there is a winter break from November to April. You can also see the tower from outside in the Ringbahn series, part 5.

03 Underground to freedom · Mitte

about 1 minute from Bernauer Straße U-Bahn station to the meeting point

Directions in Google Maps · Official site

The story of the escape tunnels under the Wall: according to the association more than 75 tunnels are known, only 19 succeeded, and up to 450 people got from East to West Berlin through them. The highlight is a look into the only surviving original escape tunnel from 1970/71, nine metres underground, reached through a visitor tunnel about 30 metres long. The meeting point is Brunnenstraße 141. Recommended from year 10 at the earliest. Afterwards, the Berlin Wall Memorial a few steps away is worth a visit.

04 Fichtebunker · Kreuzberg

about 8 minutes on foot from Südstern U-Bahn station

Directions in Google Maps · Official site

A bunker you would not recognise as one: in 1941 and 1942 it was built inside a disused 19th-century gasholder, with six floors, 600 rooms and space for 6,000 people. After the war it was a refugee shelter, youth prison, old people's home, homeless shelter and finally a secret West Berlin reserve in case of another blockade. Today glass-fronted flats sit on the roof. Meeting point Fichtestraße 6.

05 Nuclear bunker Pankstraße · Gesundbrunnen

Directions in Google Maps · Official site

In Pankstraße U-Bahn station there is a multi-purpose shelter from the 1970s, listed since 2010. More than 3,000 people were to find protection here for two weeks, with its own waterworks, reinforced concrete gates and emergency power. The tour also asks about the state of civil protection today. Another Cold War tour leads into the site at Blochplatz, which was makeshift-converted into a shelter between 1981 and 1983.

No tour, no ticket

06 Exhibition Border and ghost stations · Mitte

inside Nordbahnhof S-Bahn station, entrance on Gartenstraße

Directions in Google Maps · Official site

During the division, West Berlin trains ran beneath East Berlin through stations that were sealed and guarded. On the mezzanine of the former ghost station Nordbahnhof, an exhibition by the Berlin Wall Memorial explains this history with case studies, and the former blocking walls are marked in the floor. Entry is free, and it is open while the S-Bahn runs.

07 Boros Collection in the Reichsbahn bunker · Mitte

about 6 minutes on foot from Oranienburger Tor U-Bahn station

Directions in Google Maps · Official site

A bunker full of contemporary art: in a converted bunker at Reinhardtstraße 20, collectors Karen and Christian Boros show changing selections from their collection across 3,000 square metres. You can only get in on a guided tour with a ticket booked online.

If you want more dark chapters after the underground, see Behind bars. And on a grey day the tours fit well into our plan for Berlin in the rain.