A little way off, try The Outside Chance in Manton. Very good, indeed.
It was better when it was the Oddfellows Arms and served 14 year olds industrial quantities of 6X. When I was 14 of course and looked at least 12.
There is a place to park less than 400yards from the Red Lion, but only three cars can fit if they park carefully, so forgive me if I don’t blab it’s location far and wide
I know exactly where you mean CZ, best we coordinate visits as I’m not great at parallel parking 😀
Personally I’d park at the Sanctuary on the A4 and walk to Avebury if I were unencumbered by children, there’s a nice circular loop possible.. would take a while though.