Complex engineering and metal-work discovered beneath ancient Greek 'pyramid'

Latest find on Cyclades' Keros includes evidence of metal-working and suggests the beginnings of an urban centre, say archaeologists

More than 4,000 years ago builders carved out the entire surface of a naturally pyramid-shaped promontory on the Greek island of Keros. They shaped it into terraces covered with 1,000 tonnes of specially imported gleaming white stone to give it the appearance of a giant stepped pyramid rising from the Aegean: the most imposing manmade structure in all the Cyclades archipelago.

But beneath the surface of the terraces lay undiscovered feats of engineering and craftsmanship to rival the structure's impressive exterior. Archaeologists from three different countries involved in an ongoing excavation have found evidence of a complex of drainage tunnels - constructed 1,000 years before the famous indoor plumbing of the Minoan palace of Knossos on Crete - and traces of sophisticated metalworking.