Bulgarian archaeologists have unearthed 15,000 miniature golden rings that date back to the end of the third millennium BC.

They say the treasure is a find that equals the famous treasure of Troy.

Many of the rings are so finely crafted that their design etchings are invisible, even with the use of an ordinary microscope.

The golden ornaments have been gradually unearthed over the past year from an ancient tomb near the central village of Dabene, 120 km east of Sofia, the capital of Bulgaria.

The site consists of an ancient settlement and three burial mounds.

Archaeologists on site have not identified the ancient inhabitants.

They say they are likely ancestors of people who lived in what is now Bulgaria and parts of modern Greece, Romania and Turkey until they were assimilated by the invading Slavs in the 8th century AD.