The construction of a metro network beneath the Greek city of Thessaloniki has unearthed an extraordinary treasure trove of ancient artefacts, from gold wreaths and rings to statues of the goddess Aphrodite.

The progress of the metro system has been delayed because of the sheer number of items that have been found beneath the streets of Greece’s second city.

Archeologists have dug up more than 300,000 artefacts, from coins and jewellery to marble statues, amphorae, oil lamps and perfume vases.

They were found in what would have been the thriving commercial centre of the ancient city, which was the second most important conurbation in the Byzantine Empire after Constantinople.

During the construction of the metro network, archeologists found a stone-paved road, the Decumanus Maximus, which would have run through the heart of Thessaloniki in the sixth century AD, as well as the remains of villas, shops, workshops and an early Christian church.

More than 5,000 tombs and graves were uncovered, some of them containing exquisite golden wreaths.

“The excavations are the biggest archaeological project of recent years in Greece,” Yannis Mylopoulos, the chairman of Attiko Metro, the company building the network, told The Telegraph.