Littlestone,
You need to download the annoying ActiveX thingy. It prompts you when you click on the empty space where the image should be. Once downloaded, use your arrow keys to "walk" amongst the stones. It's not bad, and gives an idea of what it "might" (my word, and inverted commas) have looked like from within the trilithon circle - very closed in.
Regards,
TE.