Yesterday I took the S-Bahn from my local train station in the suburbs of London. At the terminus at Wasserklo I took the Nördlich U-Bahn Linie to Königskreuz St. Pankraz, changing onto the Städtich Linie and finally alighted at Grashügel. No. Wait. That's not right.

What I actually did was take the South West Trains suburban line into London Waterloo, hopped on the Northern Line to King's Cross St. Pancras and then changed onto the Metropolitan Line and got off at Farringdon. What's going on here?

This is another mass transit map, but this time it's not of the London Underground system, but the U-Bahn and S-Bahn system in Berlin. The name U-Bahn derives from Untergrundbahn, or underground railway whilst S-Bahn comes from Stadtschnellbahn, or fast city train.

As a general rule of thumb, the London Underground is, as the name suggests, underground in the centre of the city and surfaces as you move into the suburbs. The same can't be said of the U-Bahn and S-Bahn, which is underground and overground in pretty much equal measures over a lot of the network.

But this post is not about the official map of Berlin's transport, it's about this, unofficial, map of Berlin's underground and not so underground trains.