They have to fence it off because it's so accessible. Tell you a story… We were visiting Isla and missed the bus to the Ardbeg distillery. A one-eyed old boy (Mick) overheard me moaning and offered to drive us – cool!
After the tour, we had lunch with Mick then he suggested we visit the Kildalton Cross nearby. I'd read a little about it and it was a sunny day so agreed. He drove slowly and stopped by a little deserted churchyard. My jaw hit the floor and I was misty eyed (I am just thinking about it)!
I stood on it, touched it all over, embraced it. It's the most beautiful man-made thing I've seen and it's 1200 years old. And it's just standing there quietly and uncelebrated in that little churchyard
It's a joke, I just came back from the Yosemite in the states. 20 dollars to take a car in for 7 days, lots of amenities, free walks / tours / classes by rangers, and yet it's all done tastefully and with better customer service than you'd ever get in the UK.