>how we can protect this site from future vandalism

That's the issue I guess. It's not possible to go back and prevent the people who lit the fire from lighting it, but it might be possible to prevent them (and any potential copycats) from wanting/being able to do so in the future.

Lighting fires at any site, unless done in such a way as to ensure no physical damage, *is* vandalism, and as such is inexcusable. It's a lot more clearcut than the issue of people leaving tat. I'm sorry to anywho think we should all have the right to do as we please at our ancient sites, I know that people will have lit fires for various reasons in the past, but that was then and this is now. There's a lot more people visit places like Callanish these days, remote location or no.

Look at the state of the twelve apostles on Ilkley. Do we want Callanish to end up in that state? Or (equally vile to contemplate), do we want it to end up needing a wire fence and security cameras, entrance fees etc?

Gah! Rant over.