It was the largest, most impressive port in the Roman Empire when it was inaugurated in 10 B.C.E. And some 2,016 years later, the ancient port of Caesarea -- along the Mediterranean coast of Israel -- was inaugurated again last month, this time as the world's first underwater museum.
Divers can now don their wetsuits and tour the sign-posted remains of the magnificent harbor built by King Herod to honor his Roman patron, Caesar Augustus. The site has been excavated over the last three decades by a team led by the late professor Avner Raban of the University of Haifa's Recanati Institute for Maritime Studies.
It's not your ordinary museum tour. Visitors float from one "exhibit" to the next, marveling in silence at the untouched remains of a once-glorious harbor: a Roman shipwreck, a ruined lighthouse, an ancient breakwater, the port's original foundations, anchors, pedestals.
"It's a truly unique site," said Sarah Arenson, a University of Haifa maritime historian and participant in the project. "This port was built as the state-of-the-art port of the Roman Empire, and made the other ports of the time, including those of Rome, Alexandria and Piraeus, look small and out-of-date by comparison."
Arenson notes that the port is also unique today: "There are no other ancient ports in the world that are accessible to ordinary divers," she said.
Some such ports are restricted to authorized scientists. Others may be open to any diver, but would be meaningless to such visitors "because," Arenson explained, "all you would see is a bunch of stones."
At Caesarea, divers view some 28 different sign-posted sites along four marked trails in the sunken harbor covering an area of 87,000 square yards. Divers are given a waterproof map that describes in detail each of the numbered sites along the way (currently maps are in English and Hebrew; within a few months they will be available in six additional languages). One trail is also accessible to snorkelers; the others, less than eight yards below the surface, close to the beach, are appropriate for any beginner diver.
And what does the visitor see?
In a sense, an abrogated history of this once prominent port town -- from its entrance at sea (about 100 meters from the current shoreline) to the Roman shipwreck that signaled the demise of the port -- probably due to an earthquake -- about a century after its construction, researchers believe. And, in between, divers can view the remnants of the original foundations that made this harbor one of the wonders of the Roman Empire.
"This port was built using the knowledge and technology of Roman engineers," said University of Haifa maritime historian Nadav Kashtan, a member of the team that excavated the site.
The port was built with a type of hydraulic cement, invented by the Romans, known as pozzolana.
"The Romans found that when they take the volcanic powder found around Mount Vesuvius and mix it with lime and rubble, the substance hardens in water," Kashtan said. "This hydraulic concrete was imported to Casearea and used to fill wooden frames which were then lowered into the water to lay the foundations for the port."
Two such frames were found, one almost perfectly intact, and are on view today.
Kashtan noted that thousands of men were recruited -- both from Rome and locally -- to build the port in the course of 12 years. Among them were many divers, who descended simply holding their breath, or possibly in a diving bell.
The Roman city of Caesarea was built on the ruins of a decaying Phoenician town called Straton's Tower. Its builder, Herod, who also built the Second Temple of Jerusalem, was considered one of the most magnificent builders of the Roman era, Kashtan notes.
The Jewish king built the town -- given to him as a present by Augustus -- into a grand, fortified city that served as the capital of the Roman province of Judea for about 600 years.
The underwater park was developed with the financial support of the Caesarea Development Corporation.
Israel has long been known as a diver's mecca because of the rainbow of corals and exotic fish found off the coast of the Red Sea resort of Eilat. But the country has more than two-dozen other diving sites along the Mediterranean coast -- from the unique maze of chalky white caves of Rosh Hanikra in the north, to a collection of shipwrecks dotting the coast as far south as Ashkelon.
The sunken port of Caesarea -- with its ancient sites and modern explanations -- is sure to become one of the top underwater attractions.
Leora Eren Frucht is an associate editor of Israel21c.