i think the moon theory could be correct because when you think about it if the weapon machines were actualy located anywhere near the land its more likely that the land would be blacklands. I think the great white occured far away from the land which is why its still habitable. i dont think elspeth would go to the moon, that seems just a bit ridiculous, i think its just the control machines for the weapon machines that elspeth must find and 'disable'. And its been said that this was netrual ground, and no not switzerland, so i think it may mean under water?? Interntational waters would be nuetral jurisdiction so i think this is where elspeth must go.
I think Entina might have been a decoy, and that it be a nice twist for the weaponsmachines to be in the Agyllian's eyrie.
How about the centre of Antarctica? Seeing as its whole entity is not governed by the one country. Not exactly neutral, but it's close? ~:|
Moon, undersea, Antarctica and Arctic are all very valid neutral territory. In fact I am convinced it is the Moon thanks to Maruman and other hints.
I think people forget that Atthis said Elspeth only need to DISABLE the machines permanently, and frankly, even the destruction would be computer controlled, how else do you expect her to destroy the missiles? By hand? Stones? Pickaxes?
Entina seem to be the location of the entrance to the control room and it kinda make sense, probably using lasers to kill people who got too near. All you need to do is to access the control panel, disable the Balance of Terror program, causing it to be disabled permanently perhaps even automatic dismantled. (In fact i have been wondering whether BOT would be activated again if Slavers of the Red Land invades the Land, and vice versa).
I have a really strong feeling that one can access the place where the weapon machines are in the silent vale. Inside the vale there is a deep chasm in which Elspeth threw a stone. It took a long time for it to reach the ground and there were strange reactions to this. As I have read many theories about the role the moon might play in this, I had the idea, that only at one special time, the moonlight gets down in the chasm just about like it is only possible to descend into the vale around midday.
My sister and I do believe that BOT/Guardian is on the moon because of how many references Maruman makes about hating it.
‘I tried to force the vision not to come, but it was impossible. I stared up at the moon. It had become a penetrating yellow eye. I knew that eye sought me, and I felt the panic rise within me.’
Obernewtyn
‘Instinctively, I glanced up, seeking the pitted face of the moon. Maruman had always attributed his darkest foresight to it, and I had come to see it as a bad omen, too. As if summoned by my thoughts, the moon suddenly sailed clear of the clouds.
I felt a mindless rush of fright at the sight of it glaring down on me like the eye of some unearthly hunter. But even as I laughed at my melodramatic imagination, I felt oddly unsettled, and it took me a long time to sleep.’
Ashling
And several others indicating it. However, a few other places have come to mind. Possibly under Obernewtyn or of course in the red queens land.
Spoiler:
I seem to recall Elspeth having a vision in TS where missiles came out from underneath Skylake not to mention the empty missile silo on Norse Island so I don't believe the actual "weapon" part of the BOT unit would be on the moon, but scattered throughout the world.
Also, even though a nuclear war would probably melt Antarctica, I think it is possible that it is there. Think if Elspeth had to take a submarine to disarm sentinel. The submarine could have been built by Jacob.
I just re-read the Sending and it seemed to be saying more clearly than the previous books that Elspeth's quest is focused on the Sentinal Program and NOT the BOT computer + weapon machines. If her goal is to disable/destroy/dissuade Sentinal, rather than physically destroying the weapons themselves then it makes sense to me that they (and probably the BOT program) are on the moon, because that is the only way destroying Sentinal effectively renders them harmless. If the missiles are still hidden in places like the Silent Vale, they could still feasibly be used by someone with knowledge of technology. If they're on the moon and the only way to use them Earth has been destroyed then Elspeth's post-Great White world is safe.
She is to disable Sentinal, not destroy it, I think. You do make a good point on how if the weapon locations are on Earth that one day they might be reactivated but I'm pretty sure there was a vision in TS that showed missiles going out from skylake
But weren't they the missiles that caused the original Great White? I had understood that there was an accident with the test Sentinal in Old Scotia before the actual Sentinal and BOT computer went online. The second Great White would be Ariel waking up the actual Sentinal, which would register the Great White as an act if aggression between the powers and trigger the Balance of Terror program to unless the retaliatory strike.