On an island off Britain's northern tip, new discoveries suggest a huge Stone Age ritual complex is older than Stonehenge.
But age is only the half of it. Researchers say the site may have in fact been the original model for Stonehenge and other later, better-known British complexes to the south.
First discovered in 2002, the waterside site- called the Ness of Brodgar ("Brodgar promontory")- lies on Mainland, the largest of Scotland's Orkney Islands (map).
According to recent radiocarbon dating of burned-wood remains, the Ness was first occupied around 3200 B.C. and went on to include up to a hundred buildings within a monumental walled enclosure.
By contrast, the earliest earthworks at Stonehenge date to about 3000 B.C. And it would be roughly another 500 years before the first of the famous stones were set on Salisbury Plain.