Where is it? Akerman Rd, between Myatts Fields and Mostyn Gardens, Camberwell.
What's quirky about it? It's just the protrusion into our universe of a boiler room thing below the road, but it looks just like a submarine. They should paint it seakelp green, and put a periscope on it. Actually, inside it looks pretty much like a sub too, only without the sweaty sailors desperate for a fag stop.
Why bike there? Myatts Fields is quite a nice little park and has a large scale map of the world you can walk around, though its geographic accuracy is open to question. You're not far from Kennington Park (with a nice little cafe) or Brixton.