United Kingdom

so if you stayed in Gloucester the whole time, it'd mean a lot of travelling. It would make more sense to divide it into 2 - Peterborough, Leicester and Lichfield in one (plus Southwell and Derby if you can), and Hereford and Gloucester the other (plus Worcester).

(Southwell is an odd place to find a cathedral - quite likely the least known cathedral in the country. The town is so small, it doesn't have its own railway station - there's a small one a couple of miles away. So either hope for good weather and a country walk, or book a taxi.)