Underwater excavations of the ancient city of Corinth have uncovered monumental piers and evidence that the sunken port of Lechaion functioned as a booming trading hub for over a thousand years.

Ancient sources speak of Corinth as a wealthy trading center with a mixed population of Greeks, Romans, and Jews. According to the Greek Scriptures, it was in the Corinth synagogue that Paul the Apostle preached and sparked controversy among its members. Now, recent underwater excavations by a team of Danish and Greek archaeologists have uncovered the infrastructure of a major harbor, and evidence of vibrant maritime activity spanning the 6th century BCE to the 6th century CE.

“Lechaion is one of the most important harbor towns of antiquity, and what makes Lechaion so special is that it had been in virtually continuous use for more than a thousand years from around 600 BC until the late 6th/early 7th century AD," says co-director of the underwater excavations, Dr. Bjørn Lovén from Copenhagen University. "We hope that we will be able to understand how Lechaion and other harbors developed over this wide span of time."

The underwater excavators have been exploring the harbor for two years. The recent discoveries include two monumental piers constructed of ashlar blocks along with a smaller dock, two areas of wooden caissons, a breakwater, and an entrance canal leading into Lechaion’s three inner harbor basins.

Open gallery view Maritime archaeologist investigating huge building stones at the outer part of the entrance canal to the Corinthian port of Lechaion. Credit: Vassilis Tsiairis

Corinth: Portal to the West

Corinth lay on an isthmus between mainland Greece and the southern peninsula, the Peloponnese. The isthmus was less than six kilometers (4 miles) wide at its narrowest point, so Corinth had two ports. Lechaion lay on the Gulf of Corinth, serving sea routes heading westward to Italy, Sicily, and Spain. On the Saronic Gulf, Kenchreai served maritime traffic to and from the Aegean region, Asia Minor, Syria, and Egypt.

Open gallery view The port of Lechaion was central to the service of Corinth and was a trading hub to the entire region for over 1,000 years. Credit: Map by ASCSA

“Corinth ranked among the most economically and militarily powerful, and enduring, cities of antiquity. The city lay with an exceptional geographical advantage on the northeastern tip of the Peloponnese and controlled the isthmus that facilitated land travel between northern and southern Greece, and travel by sea between the western and eastern Mediterranean,” explains Lovén.

Navigators often preferred to anchor at one of Corinth's two ports and have their cargo transported overland, due to the windswept nature of the capes at the southern extremity of the Peloponnese. Lightweight ships could be hauled over the isthmus on a platform that ran along a grooved pavement from sea to sea.

“According to ancient sources, most of the city's wealth derived from the maritime trade that passed through her two harbors,” Lovén adds.

Early Byzantine construction secrets

The team of archaeologists has discovered the remains of an early Byzantine pier constructed of six well-preserved wooden caissons, stretching a total of 57 meters in length, and a stone-lined entrance canal to the little-explored Inner Harbor of Lechaion.

Architect Chris Brandon has studied the caissons at Caesarea Maritima, and believes both the Lechaion and Caesarea caissons were "single mission barges" – essentially rectangular wooden frames, with floors so they could float. The caissons would have been built onshore before being floated out to predetermined locations and sunk using concrete or rubble. They created a harbor breakwater or pier, acting as a barrier from the wind, whilst protecting moored ships and their cargo.

The caissons discovered in Lechaion are the first of their kind ever discovered in Greece with their wooden elements still preserved.

“These large wooden boxes were left in situ to contain the fill whilst it set or consolidated, and have remained largely intact as they rapidly became submerged into the seabed that preserved them,” says Lovén.

Open gallery view An archaeologist documenting a wooden caisson found during the underwater excavation of the Corinthian port of Lechaion, Greece. Credit: Vassilis Tsiairis

Structures hidden in sand

Throughout the project, the marine archaeologists have been mapping the sunken city using a range of state-of-the-art technologies.

“We conducted geophysical survey work in the sea with a team of geologists from the University of Patras, led by Dr. George Papatheodorou, and we are using cutting-edge technology, such as the a newly developed 3D parametric sub-bottom profiler," Lovén told Haaretz. "It’s the first time that this equipment has been used in archaeology. It was developed to create 3D images of structures hidden in the sand and of the layers that surround them!”

Click here for video showing diving archaeologist exploring around one of the wooden caissons.

Corinth, like Piraeus, was a city with religious diversity. Evidence of this can be seen in the temple for imperial cult, shrines and sanctuaries dedicated to Greek and Egyptian divinities, and a Jewish synagogue. Lechaion port was a mercantile hub, home not only to a diverse religious community, but also a major naval base.

Some claim that the trireme, one of the most effective battleships of antiquity, was built along the shorelines of Lechaion by the Corinthian shipbuilder Ameinokles. The Athenians used trireme’s advantages in their crucial victory over the Persian navy at Salamis in 480 BCE.

Open gallery view Remains of wooden caissons - one-time barges with flat floors that the Byzantines would float out to sea to specific spots, fill with rocks or concrete, and sink to create a breakwater. Credit: S. Kokkinakis

“According to literary sources, Lechaion had extensive military harbor works, but we have not located the naval base (or bases) – yet,” says Lovén, adding, “About the trireme – the ‘Holy Grail’ of underwater archaeology – I have only one comment. We must all keep searching, searching and searching – and never give up!"

This year the expedition focuses mainly on the excavation of the entrance canal to the inner harbor and the two massive moles, where several more wooden caissons have been discovered.