Lets see (from memory):
Cardiff, Swansea, Pembrey, Haverfordwest, Shobdon, Gloucestershire, Compton Abbass, Henstridge, Dunkeswell, Exeter, Plymouth, Perranporth, Kemble, Bournemouth, Lydd, Filton, Biggin Hill, Manston, Rochester, Stapleford, Duxford, Coventry, Halfpennygreen (as it was named then), Welshpool, Jersey, Bembridge, Old Sarum, Sturgate, Teeside, Blackpool.
That makes 30 airfields in the UK. I have also a few in France and Ireland. But the vast majority of the others are within the United States (West and East Seaboards).
I've also been to other fields in the UK in friends aeroplanes.
Best wishes,
Charlie Zulu.