As a child, Klaus Schmidt used to grub around in caves in his native Germany in the hope of finding prehistoric paintings. Thirty years later, a member of the German Archaeological Institute, he found something infinitely more important: a temple complex almost twice as old as anything comparable on the planet.

"This place is a supernova," said Schmidt, standing under a lone tree on a windswept hilltop 35 miles north of Turkey´s border with Syria. "Within a minute of first seeing it I knew I had two choices: go away and tell nobody, or spend the rest of my life working here."

Behind him are the first folds of the Anatolian plateau. Ahead, the Mesopotamian plain, like a dust-coloured sea, stretches south hundreds of miles. The stone circles of Gobekli Tepe are just in front, hidden under the brow of the hill.

Compared with Stonehenge, they are humble affairs. None of the circles excavated (four out of an estimated 2 are more than 30 metres across. T-shaped pillars like the rest, two five-metre stones tower at least a metre above their peers. What makes them remarkable are their carved reliefs of boars, foxes, lions, birds, snakes and scorpions, and their age. Dated at around 9,500BC, these stones are 5,500 years older than the first cities of Mesopotamia, and 7,000 years older than Stonehenge.http://www.guardian.co.uk/science/2008/apr/23/archaeology.turkey