We have stone circles as well here in Ireland...but we are not alone...virtually every European country has stone circles of varying sizes...some small...as in big enough for half a dozen people to stand inside the circle...some very large indeed...as in the size of a football pitch.
There doesn't appear to be a circle anywhere with stones the size of those at Stonehenge...mostly the rest of the known circles have stones which are about adult shoulder height and smaller...
Some have stones which are missing...some have one or maybe two stones which stand outside the circle on the perimeter...some have been excavated but the majority have remained untouched...
Excavations have produced small numbers of human bones...not enough to warrant a burial ground but enough to suggest that the remains may have been sacrificial victims to commemorate the building of the circle...apart from the few human bones and an occasional pottery shard, which may have been accidental...nothing of importance or value has been unearthed so far.
What were they for then...these enigmatic places seeped in the history of four or five thousand years ago...the usual astronomical observatories theory comes up time and time again...placed to catch the rising sun on the equinoxes and solstices.
Or they may have been built as a meeting place for the elders of the Neolithic tribes...maybe for worship of the stars and the moon...they could have been used for feasts and celebrations but there is no evidence remaining to suggest that was the case...no animal bones for instance or drinking vessels...no grains of wheat or oats...
Most stone circles have stories attached...the stones were once girls dancing on the Sabbath and they were turned to stone by God for doing so...the stones were Witches meeting together in an unholy coven and they were turned to stone by lightening from the skies above...
Legends of the ill fate which will befall anyone who displaces any stone in a circle...that's usually along the lines of being crushed by the stone you're trying to heave out of the ground...that did actually happen to a chap in the 1400's...he was totally squashed.
Now, in Ireland anyway, the Faeries are never associated with stone circles...no-one ever shudders at the thought of entering one in the way they do with a ring fort for instance...but some of those stone circles are downright unpleasant...the little ones on private lands where you have to find a man on a tractor to ask please, could you ever go across his fields...those are sometimes quite nasty, even with no foreknowledge whatsoever.
The big manicured circles at places like Avebury in England are far too neat and tidy and well ordered to manage to give off anything...whatever dark secrets they ever held they are keeping firmly to themselves and not sharing with hordes of gormless tourists.
So, the answer to what were stone circles built or erected for...no-one actually knows for certain. Theories and suggestions still veer towards an astronomical angle...we may never know with certainty.