Rainbows occur fairly often in Scotland, or maybe it just seems like it, because I have seen several rainbows in the Cairngorm mountains.

Mountains near the sea shore offer opportunities to look in all four compass quadrants too, which is always helpful for finding rainbows, your view not being blocked by higher ground.

Yes, I think I'm going to explore some of his road trips this spring or summer

I think the Southern SIxers looks particularly interesting.