Stonehenge 181
Image by Jane

As much as I hate it personally I think the Newgrange approach is the answer. Distant visitors' centre, shuttle buses and a fixed length, fixed size accompanied tour.

Problem is with numbers. I think about 1000 or so a day go through Newgrange and nearly twice that much visit Knowth. Stonehenge must get more. Only 50 people are allowed at Newgrange at any one time and 80 at Knowth. This does mean that on busy days if you arrive mid morning you may end up waiting around the visitors' centre until late afternoon. People do seem to tolerate this quite readily, though.

I think the accepted figure for Stonehenge (including the fence-peerers) is about 2700 a day so Knowth is a persuasive model if it works there. Fifty shuttle buses a day (or even 150 on a very busy day) seem a pretty innocuous price to pay to get rid of all the crud. After all, they'd just come, then go, not hang about in huddles.

In the Stonehenge context there would be less need for set periods for visits as well. It could stand a few hundred at any one time, especially if people could be persuaded to wander the wider landscape (which disgracefully few do at present apparently).