St Chad's

After yesterday's Blip I thought I would choose something with a bit more soul.

St Chad's (1792) one of only six round churches in UK

...and a wonderful blue sky

I have a request
My 20 something son and three friends from Australia will be visiting UK for two weeks in August. They would like to visit Bath, Stonehenge and Warwick Castle . Could you suggest any other interesting sites/sights that maybe less well known and therefore less crowded. All ideas will be considered.