More than 4,000 years ago, a naturally pyramid-shaped promontory now separated from the tiny Greek island of Keros, about 200 kilometres southeast of Athens, was shaped it into terraces and covered with 1,000 tonnes of specially imported gleaming white stone, giving it the appearance of a giant stepped pyramid - the most imposing manmade structure of the Cyclades archipelago in the Aegean Sea. Keros was a major sanctuary where complex rituals were enacted in the third millennium BCE. 4,500 years ago it was connected to the promontory by a narrow causeway.
     Archaeologists excavating an imposing staircase in the lower terraces have now found evidence of a complex of drainage tunnels, and traces of sophisticated metalworking. The water works predate by 1,000 years the famous indoor plumbing of the Minoan palace of Knossos on Crete, 200 kilometres further south.
     The first evidence of metal-working was found in excavations 10 years ago. New finds include two workshops full of metalworking debris. Artefacts include a lead axe, a mould for copper daggers, dozens of ceramic fragments from metalworking equipment, and an intact clay oven.
     Soil samples reveal traces of pulses, grapes, olives, figs and almonds, and cereals, including wheat and barley. Evi Margaritis of the Cyprus Institute says much of the food was imported: "in the light of this evidence we need to reconsider what we know about existing networks to include food exchange."
     Earlier excavations by the team uncovered thousands of marble Cycladic sculptures - stylised human figures which appear to have been deliberately broken and brought to the island for burial.
     Lord Renfrew, joint director of the excavation, believes the promontory may originally have become a focus for development because it guarded the best natural harbour on the island, with wide views across the Aegean.
     The excavations are being recorded digitally using the iDig app on iPads for the first time in the Aegean, creating 3-dimensional models of the digging process, giving everyone involved access to all data in real time.

Edited from The Guardian (18 January 2018)