Recommendations for UK city break

[Tiggles]

I want to go away for half term
Me
Two boys 11 and 13
And my mother (active pensioner)
Could you recommend a city to visit. We live in North Wales so anywhere in UK would work. Not London as went there last year or Chester as go there regularly.
Like to visit cathedrals / castles / museums / parks (but not sure on the weather)
Happy to do lots of walking
But open to most activities.

Oh, just remembered there is the monastery in the Gorton area... not been but have heard it is popular for visitors.

Thanks all
Booked into Bath but made a list of places to visit over the next year.
@osquito I go to Manchester every now and then but hadn't heard of the monastery. Will check it out next time I'm there.

I know you've booked for this year... Bus a suggestion for next time, have you considered Norwich? Two cathedrals, several museums, a castle, historic city centre...

Bath will be rammed with tourists. Still you can tick it off your list.

I would have said Portsmouth. Not particularly expensive, mild weather. and the Naval dockyard ( Mary Rose, HMS Victory and loads more) is great for your aged kids and their history knowledge.
Easy to get around, Southsea has a beach, arcades and fabulous 500 year old buildings plus a Hovercraft ( worlds only only commercial craft) to take them to the Isle of Wight. Which is also lovely.

Belfast & around NI! I'm biased but love it here, (also love Glasgow), get the ferry from Holyhead-so much you can cram in here with a car in a few days & something for everyone

We went to portsmouth about 5 years ago and the kids loved it. They still talk about it now.

Bath is a great choice. While you're there, I suggest spending a day in Wells which you could combine with Wookey Hole caves (if raining) or Glastonbury Abbey and Tor (if fine).