Oh yes, look. Gary's written yet another post about a map of the London Tube system that he likes. Yawn. Time to move on. But wait ... this may look like a map of the London Underground but it's not.
Now I may have been guilty of wearing my heart on my sleeve slightly too much where variations on a theme of the London Underground map have been concerned; there's at least seven posts on this topic already posted.
Granted, there's the Northern Line on the map; but this is more for a sense of geographical perspective than anything else.
The blue lines aren't branches of the Piccadilly Line. They're the rivers that have been long lost and yet still run under the streets of London; the Fleet, the Effra, the Westbourne and Stamford Brook. Historical point of note; the Jubilee Line was originally going to be called the Fleet Line, although the path of the line followed the course of the (also buried) Tyburn rather than the Fleet, but was renamed the Jubilee to coincide with the Silver Jubilee of Elizabeth II.
Likewise, the orange lines aren't the Overground, they're sewers, nor is the red line the Central Line, it's the Post Office railway or Mail Rail.
So it may look like a map of the Tube, but it's anything but. It's all the work of Richard Fairhurst, who's made a few maps in his time; they're well worth a look.