Our local one is
Stourhead, fabulous gardens, lot's of other walks and good local hostelries, we've not done the house as it's not particularly wheelchair friendly.
Also there's Longleat, lots to do but I'm somewhat ambivalent about the Marquis' attitude to employment, tenants, neighbours etc. so won't go there.
In fact this part of the world is overrun with amazing things to see, from pre-history through to the modern day, Stonehenge, Iron Age Forts, Bath, Salisbury, Montacute etc. etc.
Currently investigating the Hillmans of Sussex.