The "Bluestones" at Stonehenge came from the Preseli Mountains in Pembrokeshire. This is a fact, the stone at Stonehenge and at Preseli has been tested forensically.
Preseli and Stonehenge are about 182 miles apart if you use the motorway and main roads.
It is thought they must have been floated on rafts from Pembrokeshire up the Bristol Channel into the River Avon and dragged from there to Stonehenge.