North entrance was originally accessed via two drawbridges and a central island/pathway. Once Military road was re-routed and cut through a section of the North Lines the entrance was no longer used and as of the late 1960’s the remains have been left to decay. The two bridges have been burnt down leaving only the beams as a reminder of the beautifully engineered North Entrance. The North Entrance still remains hidden underground. The main point of access is via a metal door which is locked and not open to the public with no signs of it ever being opened up. However, where there’s a will, there’s a way. Via the rear entrance we managed to gain entry to the underground tunnels, gun rooms, galleries, three large water tanks and unlined tunnels to carry the pipes.

Visited this site with Frosty and fortknox0

And here’s one just for Frosty