For my DH's 70'th we took our children and grandchildren to Center Parcs at Longleat for a long weekend. Great fun for all ages - but watch out for tics in the woods! It is between London and Devon so could work for your family
My DH will be 70 and wants to take family away for a weekend. We live in London and some kids live in Devon. Any suggestions for hotels with 'facilities' near a town to SE or S of London?