Archaeologists were baffled when they discovered a genuine buried gold treasure while unearthing a wealth of findings on the Mediterranean shore.

Israel Antiquities Authority (IAA) researchers discovered the “rare and unexpected” artefacts north of Tel Aviv, in Ramat Ha-Sharon. Archaeological excavations conducted in advance of the city’s planned expansion have uncovered evidence of Byzantine-era industry in the vicinity, demonstrating that the city’s history is “far more ancient than generally assumed.” Archaeologists discovered an ancient winepress, bronze chain, and Byzantine gold from the first part of the seventh century AD among the unearthed artefacts.

According to the exposed structures, the excavated site is at least 1,500 years old.

Diego Barkan, Tel Aviv Region District archaeologist for the IAA, said: “This is the first archaeological excavation ever conducted at the site, and only part of it was previously identified in an archaeological field survey.”

The antique winepress had a lovely mosaic floor and plastered walls, implying the presence of a neighbouring farmhouse or warehouse.

Dr Yoel Arbel, excavation director, said: “Inside the buildings and installations, we found many fragments of storage jars and cooking pots that were used by labourers who worked in the fields here.

“We also recovered mortars and millstones used to grind wheat and barley and probably crush herbs and medicinal plants.

“Most of the stone implements are made of basalt stone from the Golan Heights and Galilee.”

The most astounding revelation, however, was still to come.

The IAA announced in a Facebook post: “One of the rare and unexpected finds uncovered during the excavation is a gold coin minted during the reign of the Byzantine emperor Heraclius in 638 or 639 CE.”

On one side, the Byzantine ruler is depicted, surrounded on both sides by his two sons.

The reverse depicts a cross atop Golgotha, the hill where, according to Christian legend, Jesus Christ was crucified.

This would have been an extremely precious chunk of gold 1,300 years ago, and the coin bears the owner’s name.

The coin gives new insight on the end of Byzantine control in Israel, the Persian invasion, and the entrance of Islam, according to Dr Robert Cole, head of the Antiquities Authority’s currency section.

The Byzantine Empire, or Eastern Roman Empire, was created in 330 AD, with ancient Constantinople as its capital (Byzantium).

The empire was dissolved in 1453 following a period of decline and the fall of Constantinople to the Ottomans.

The archaeological site’s additional constructions have been dated to the seventh century, following the Muslim invasion of Israel.

There is a glass-making workshop on-site, as well as a warehouse filled with four gigantic jars.

The jars would have been filled with grain and other raw materials to stop them from being spoiled or infested with disease.

Dr Arbel said: “In this period, people were not only working at the site but also lived here; we know this because we discovered the remains of houses and two large baking ovens.

The discoveries have been praised by Avi Gruber, the mayor of Ramat Ha-Sharon.

He said: “I am thrilled by the finds, and we have already started working with the contractors of the Neve Gan North project to integrate the finds within the future neighbourhood.

“I want all our residents to enjoy learning about ancient life here from late antiquity and the Middle Ages.

“We are currently planning to celebrate the cities 100-year anniversary, and these new findings give us a whole new perspective on how people once lived in this part of the country.”

Eli Eskozido, director of the Israel Antiquities Authority, added: “The material remains of the cultural heritage uncovered in our excavations, preserved for ages, are of the most important national assets.

“The Israel Antiquities Authority sees great importance in making the findings accessible to the public in partnership with local and international communities.”