On Oct 26, 10:27 pm, wrote:
The original tunnel portals were destroyed when the GN electrification
link was put in. However, the severed end of one of the tunnels, with
iron lining segments, used to be clearly visible from trains between
Finsbury Park and Drayton Park.

There's an interesting bit about a visit to the disused tunnels at:

http://tinyurl.com/ysa7hl

A very interesting page , just wish he'd taken a few more photos!

B2003