The origins of Stonehenge are unknown, but Druids do go there to celebrate the Pagan festivals etc.
I wish I could add something to this - I would advise any person reading my reply to be very very wary of calling any other person's faith in Nature - by the name of Witchcraft. That term seems to attract such a SLUR - it is a form of belief
People to profess to be Christian use it as a way of taking the "High Ground" which is something no one is entitled to do - it is a question of Belief - of Faith and various people who think they are "Better" because of their BELIEF - are so NOT
It was not used as a barometer.
used for a clock
Pagans.
At Stonehenge human remains were found as well as tools used to help constructing the henge.
limestone
Stonehenge has not been used for thousands of years so no one knows the answer to this.
Stonehenge has no official ceremonial use today, other than a tourist attraction.
clay
sightseeing and tourism.
witchcraft
Yes
there really is NO SUCH THING as witchcraft!!