Bulgaria's Valley of Thracian Kings keeps its secrets

Kazanlak

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 the valley, "only 300 of them have been excavated so far and about 35 revealed such rich burial monuments," said Kazanlak archeologist Meglena Parvin. 

EU funds have been used to restore a handful of tombs that have been opened to public view, but most remain shut because of a lack of money for repairs.