I live near Salisbury and it's amazing how many locals don't know about this clock. The Cathedral is well worth a visit for many reasons, but this alone is a pretty good one.
But that whole area is fascinating. Stonehenge is a short drive North. A slightly longer drive North gets you to Avebury.
Much closer is Amesbury, which has Blick Mead on the outskirts, with evidence of occupation from nearly 9000 years ago.
http://www.buckingham.ac.uk/wp-content/uploads/2014/12/Blick...
I got a bit distracted by the copy of the Magna Carta the last time I was there so was a bit blinkered to everything else.
Next time I'm in town I'll pop in!