Ah cool. I also would be interested to know where those corridors at Piccadilly Circus lead to, as well as Green Park.
And yeah I knew about Alperton, I really want to go to Greenford though (wooden escalator).
Shame about the door at Holborn being a solid one, I knew people used to be able to look through the metal gates onto the old platform.
I'll add Oval to my list. God I sound sad...