Parkland Walk is a disused tube line that runs across North London. You can walk or cycle along the path of the old track, through disused stations and under bridges. A friend told me about it last week and I couldn't wait to go. (Especially as I'm training for my first 10km run in four weeks! The plan is to run it, but I scoped it out on my bike first this weekend.)
I joined the path in Archway, about two miles away from where I live.
The path of the track then runs through Crouch End. This is the now disused Crouch End station.
That part of the walk ends in Finsbury Park, which I didn't realise The New River runs through. The New River is a man-made river which pops up in random places in North London. And which is also totally ripe for a cycle, I reckon.