Just a question: all locations are accessible throughout the whole day, yes? So, not in any tidal regions (as in not flooded at some point in the day)?
I'm not sure about cornwall, I was thinking about the "oldest in England" bit which might be about the burial site which would put it in cider country I think?
Legend of King Arthur puts him in about 8 different places!
The reason I didn't get too excited about Marlborough is because the picture in the clue looks like a cave, which made me lean towards Merlin's Cave in Cornwall.
Still no idea what the thing in the picture actually is
Found a picture of the grotto. Definitely looks closed off to the public. And from the sounds of it, Marlborough College doesn't like people snooping around their campus
It didn't look like a cave to me it looks more like open air with the way the algae has grown on it. I know its dark but they could have taken the piccy in the evening. Thats why I was leaning towards glastonbury ruins in somerset, its one of britains oldest Christian burial grounds and is one of the places merlin was supposed to be buried along with Arthur and Guinivere.
Sadly too far for me to go and have a look at the min but it does look like the sheltered bit in the middle of the site.
Just found almost the exact same picture on the internet, taken from a slightly different angle. The problem is it's quite expensive to gain access to this place so I'm assuming that the coin is located outside. I seem to remember when I went a few years back that some of the site does have public access. Unfortunately the person that took the picture wasn't specific as to where in the site is was taken. There are leaves on the ground though.
I know a lot of the caves around cheddar gorge are expensive to get into... but I can't remember any of them having anything to do with Merlin. Either I'm going down the wrong path with the cave theory, or I'm looking too much into the Merlin part of the clue.