Stonehenge may not look very portable, but scientists say part of the massive ancient monument may have been first built somewhere else before being moved hundreds of years later.

The new finding, published on Monday in the journal Antiquity, traces the bluestones -- or the smaller stones used at the 5,000-year-old monument -- to two quarries in Wales. 

But while the mystery of where the stones came from may have been solved, a new one has just emerged: Those stones were pulled from the quarries some five centuries before Stonehenge itself was built in what is now Wiltshire, 140 miles away.