In the fields of Bulgaria they are everywhere — hundreds of mounds like huge molehills concealing the gold-filled tombs of ancient kings who left no other trace of their rule. Known as tumuli, the burial mounds are the only remnants of the Thracian civilisation that inhabited the Balkan peninsula from the 2nd millennium BC to the 3rd century AD. The accidental discovery of a tomb in 1944 revealed that the earthen structures were in fact manmade and that the burial monuments hidden within contained intricately crafted treasures. Experts believe there are more than 15,000 of these tombs in Bulgaria, a tenth of them in the so-called Valley of the Thracian Kings near the central town of Kazanlak. Many of the tombs have been looted, but a collection of surviving gold, silver and bronze objects are being shown at the Louvre museum in Paris until July 20. Of the 1,500 tumuli in

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