Note that Bath has a modern Thermal Spa that anyone can use - though you will probably have to pre book.https://www.thermaebathspa.com
It can be hard to find a hotel with parking in Bath - well, after all, most of the place was built in the late 1700’s.
If you have a car, places that are a relatively short distance that you may want to see are Dyrham House to the north of Bath and the village of Castle Combe which is NE of Bath. South of Bath, Cheddar Gorge (caves) combined with the small city of Wells should be considered.
SE of Bath is Longleat House = a historic house & safari park. This could be combined with Stourhead Garden - really landscaped parkland with temples around a lake. Alternatively, Stonehenge could be added to a trip in this SE direction from Bath
About a 40 minute drive away is the medieval castle at Chepstow - just over the Severn estuary in Wales - use M48 bridge. This could easily be combined with the lower Wye Valley which contains the ruins of Tintern Abbey. You could also visit the viewpoint at Yat Rock on such a day trip.
Also consider another trip into Wales and leave M4 at Junction 32 and drive the short distance to see Castell Coch. Then return to M4 and proceed west to next junction (33) & head south on A4232 for about 2 miles to turn HARD left into St.Fagans Castle & Museum - which needs at least 2 hours to walk around. Cardiff city centre (traffic congestion) with its castle is also worth visiting as is Caerphilly Castle to the north.
I've given you enough stuff to act a week! Google the places mentioned..
