Geologists have identified the source of some of the rocks forming Stonehenge as two quarries in Pembrokeshire.
The bluestones that form the inner ring of the WIltshire monument were known as early as the 1920s to have originated in the Preseli Hills.
However, recent excavations have confirmed that the stones came from Carn Goedog and Craig Rhos-y-felin, according to archaeological journal Antiquity.
The project’s director, Prof Parker Pearson, said: “Stonehenge was a Welsh monument from its very beginning.
“If we can find the original monument in Wales from which it was built, we will finally be able to solve the mystery of why Stonehenge was built and why some of its stones were brought so far.”
The team plan further excavations in 2016.