Most of it tbh to be honest, obviously not counting travelling through..
In England, I’ve only been to manchester, newscastle, liverpool, london, glastonbury, portsmouth and coventry.
Never been to wales.
Never been to any of the scottish islands apart from Arran.
In Scotland I’ve only ever made it as far north as Golspie and Torridon.
Belfast and Downpatrick would be the only really places I’ve been to across the water in the occupied north. 😆
Plenty exploring still to be done. I would think it’s unusual that people have seen the whole of the landmass or covered most of it. we are creatures of habit and generally holidaying abroad is more popular I think.