Some say that this establishment, Saxa Vord, was a prime target for a Soviet Bomb.
At one time there was no way up here without attention.
It has rows of tube lights that face outward of the fence, the reason for this is shown above, the gunner gets a good view.
The tunnel does not go to the top, there are comments that there are underground bunkers here, the tunnel would disguise the numbers of folks using it perhaps.
But the drain could be a way in. (Famous Five thinking) All that security and they forget the drain, I think not.
Just beyond the fence and the lights you can see Muckle Flugga
And look the other way you can see the shore station for the Muckle Flugga Lighthouse