The free Isis just arrived this morning:
So here is the full story:
On first glance it looked like one of those arrow slits in a castle wall, but then I realised it was set in concrete so more likely to be a gun hole in a more modern defensive structure. My first thought was a pill box and I found that quite a few around the coast have fallen from eroded cliffs and inverted into the beach below. The picture didn't look like a beach though.
So then I Googled BOX, TOPSY and TURVY and found that the connection was Box Hill near Dorking in Surrey. A local eccentric Major Peter Labelliere who died in July of 1800, requested to be buried vertically, head downwards, on the top of Box Hill. Apparently Labelliere had reasoned that as the “world is turned topsy-turvy", when Armageddon comes, he would be the only one to end up the right way up.
His grave is indeed at the top of Box Hill:
It lies just to the West of Box Hill Fort, one of a line of 13 mobilisation centres built in the 1890’s to protect London from the threat of invasion from continental Europe. They have never been used and have mostly fallen into disrepair.
As seen it this picture, the mystery location is one of four what I now know to be called 'Gun Loopholes'. In fact it is the most Westerly one nearest the grave.
I guessed that the phrase "A free Isis up for grabs." was probably significant and that the coin was most likely to be found above the loophole and it was, buried quite deep in a large crack that had then been filled with dead leaves etc.:
Coin removed from the crack for clarityHere's a few more pictures of the fort and the view from the hill looking across to Dorking.
Western end of Box Hill FortEastern end of Box Hill FortDorking from the Viewpoint on Box HillSo a good day out, the weather was dry but it was very muddy under foot so didn't get a chance to do much walking. It was a particularly good location because the fort is slightly off the main thoroughfares so you can snoop around to your heart's content without the danger of being arrested. Also you can actually 'drive' up the hill and there is hot food, really good filter coffee and toilets right next to the fort. What more could you ask for ?