have reported that archaeologists in Bulgaria have discovered a 1600 year old mosaic in downtown Sofia. The mosaic was built over a Roman hypocaust underfloor heating system, and was believed to be part of the home of an affluent citizen of the Roman city of Serdica. Serdica was originally a Thracian settlement but was conquered by the Romans in 29 BC. The mosaic was discovered under a concrete block supporting Dondukov boulevard.

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