If there’s a good day for winter snorkeling in Vatika Bay in southern Greece, it’s today, February 26. The temperature is 57 degrees Fahrenheit on Pounta, a beguiling beach of big, golden sand dunes. The sea is a vivid cerulean blue, smooth as butter. On the coast, between the dunes and the rugged remnants of a Roman quarry, stands a cemetery that dates back before recorded history — 70 rock-cut tombs, which are only the tip of the ancient iceberg. Just a quarter mile off the coast from Pounta unfolds the world’s oldest sunken city: Pavlopetri, 5,000 years old.
“Try out this snorkel and this mask,” says Barbara Euser, president of the Greek chapter of the nonprofit Alliance for the Restoration of Cultural Heritage (ARCH). She will be guiding me today on my first-ever snorkeling trip — not around a coral reef, but into the past. I head into the water, which ought to be frosty cold in the dead of winter, but I don’t feel a chill — rather, I feel a peculiarly uplifting euphoria.
I only need to wade through 4 to 6 feet of water to connect with the concealed city. The first things I spot are clusters of jagged stones, stippled ochre, gray, and green and arranged in straight lines. I swim farther from the shore and see a tomb made of four slabs of stone, with a fifth slab over the top.
A few feet out, we reach perhaps Pavlopetri’s most emblematic landmark. With her forefinger in the water, an excited Euser is pointing to the ruins of a big building. Ten tall, narrow stones mark the building’s east wall, and smaller stones to its south and north shimmer in the water-filtered light. This one was obviously a big public-function edifice. Why am I getting Stonehenge vibes?
Time flies by. I’m hooked: dive–prehistory–out–breathe–dive. Underwater, I catch fast glimpses of the remains of streets, houses, parks, even unknown buildings. For a human alive in the era of the metaverse, seeing an immortalized time capsule just a few meters below her feet, in which people — just like her — went about their lives millennia ago is existentially awakening.
Underwater cities are abundant off the coast of Greece, because the eastern Mediterranean Sea is a hotbed of volcanic and seismic activity. The seabed is trapped among the African Plate, moving north; the Eurasian Plate, which is static; and the Turkish-Arabic sub-plates, moving north-westward.
Yet Pavlopetri stands out among Greece’s submerged ruins, says Nicholas C. Flemming, the British marine geo-archaeologist to whom Pavlopetri owes much of its visibility. “Pavlopetri is unique because of its age, and because of the completeness of preservation of numerous structures we see in a waterfront town of the Bronze Age,” says Flemming. Pavlopetri, founded before 3000 B.C., predates Plato’s fable of Atlantis, the utopian island that disappeared into the ocean, taking with it wisdom that could bring world peace. In fact, it’s been hypothesized that Pavlopetri may have been Plato’s inspiration for the Atlantis myth.
That this age-old submerged city is historically important does not safeguard it from peril. Breakers crashing onto the shore — the wind can climb up to 40 knots in the area — cause the sunken city to weaken over time. Geotectonic shifts might be causing the site to sink deeper. Salinity could affect the integrity of the ruins. But the biggest threat to Pavlopetri might come not from nature, but from humans.
In 1904, Greek geologist Fokion Negris reported finding an ancient city in the seabed off Cape Maleas, the southeasternmost cape in continental Europe. In 1967, Flemming rediscovered and popularized Pavlopetri — which shares its modern name with a nearby island, as the city’s ancient name remains unknown. Flemming, on the hunt for Bronze Age settlements on the southern coast of the Peloponnese, arrived at the historic peninsula that summer with a checklist of 18 coastal ruins. On the shore in the Bay of Vatika, he met a family of German campers, who took him snorkeling to the islet of Pavlopetri once he told them what he was looking for.
“Suddenly I was staring down through 2 meters (6 feet) of crystal-clear water at a tangled mesh of walls, rooms, and tombs, all made of irregular stones,” Flemming writes in his recently published memoir, Apollonia on my Mind. “The strange patterns of walls, none of which was straight, mystified me … Human purpose was undeniable.” He spent the next two days measuring and sketching the walls and taking photographs of the underwater site.
Back in England, Flemming undertook painstaking research at London’s Institute of Archaeology, which led him to find out that the box-like tombs were actually cist graves: prehistoric European coffins made of stone or a hollowed-out tree. He was instrumental in obtaining a permit for diving archaeologists from the University of Cambridge to spend a month on the submerged city. The team used Flemming’s reports and sketches to survey Pavlopetri using a fixed grid system and hand tapes. The survey resulted in a map of the town, which lay in 3 to 12 feet of water.
“Pavlopetri had merchants and long-range shipping activities, people handling equipment on the docksides, and vessels sailing from one commercial center to another, probably as far as Egypt, the Levant Coast, or Sicily.”Nicholas C. Flemming, a British marine geo-archaeologist
Cambridge scientists identified at least 15 separate buildings, courtyards, streets, two chamber tombs and at least 37 cist-graves. They also recovered stunning ceramics, obsidian and chert blades, and a bronze figurine. The artifacts suggested a date range from 3000 B.C. to 1000 B.C. — the same era when the stone circle of Stonehenge was erected in England and the pyramids of Giza were built in Egypt. At that time, coastal towns like Pavlopetri developed into port cities for trade fleets. “In Pavlopetri, you have merchants and long-range shipping activities, people handling equipment on the docksides, and vessels sailing from one commercial center to another,” says Flemming, “probably as far as Egypt, the Levant Coast, or Sicily.”
In the decades after he found Pavlopetri, Flemming rose to top jobs at the British Oceanographic Data Centre and the International Oceanographic Data and Information Exchange. In 2007, he went back to Greece to check on the ancient city. An accident 37 years earlier had paralyzed him from the chest down. He conducted a reconnaissance of Pavlopetri — sometimes employing friends to lift him from his chair into the sea — to check on the city’s condition and was surprised to see it had withstood any geological threats.
The real danger came from the land. Laconia, the southernmost region of mainland Greece, was rapidly industrializing, and hordes of tourists were visiting the previously secluded area. Flemming wrote a report to the British School of Athens, an archaeological research institute, calling for “somebody” to protect the site and survey it using modern techniques. In 2009, two Greek government agencies teamed up with the University of Nottingham on the Pavlopetri Underwater Archaeology Project, a five-year effort to outline the submerged town’s history, development, maritime significance, and the reasons behind its sinking.
Advances in technology helped the researchers probe Pavlopetri between 2009 and 2014. A sophisticated surveying instrument called a robotic total station enabled a single operator to perform inspections of the underwater city remotely. Sector-scan sonar produced pictures by sending out a sound wave that reflected off the remains on the seafloor. Scientists at Sydney University deployed an autonomous underwater vehicle, which exploited the then-new technology of photogrammetry, which derives accurate measurements from photographs. The scientists digitally reconstructed the entire 15-acre area of Pavlopetri, down to a resolution of a few centimeters.
“It was surreal scenery,” recalls Peter Campbell, who worked on the Pavlopetri project when he was a maritime archaeology student at East Carolina University. “We’d be underwater with scuba equipment for two hours at a time.” The site buzzed with marine scientists, geophysicists, conservators, ecologists, and curious tourists. “Pavlopetri was one of the first projects to use large-scale photogrammetric mapping,” recounts Campbell, now a lecturer in cultural heritage under threat at Cranfield University in the U.K. “Technology has improved, but the cutting-edge techniques that were used are still being used today.” A BBC documentary about the project offered stunning visuals, including computer-generated images approximating what the ancient city would have looked like in its heyday.
Nine thousand square meters of new buildings were added to the previous knowledge of the undersea city, including a large rectangular hall and a street lined with buildings. Most important, the pottery recovered revealed a far older occupation of the site, from the Neolithic Era, as early as 3500 B.C. “In the Neolithic, Pavlopetri was a settlement where people fished, mated, and went about their lives,” says Flemming.
Pavlopetri was a model city for its time. “Thick wall foundations could have supported buildings two stories high,” says Flemming. “Curved roof tiles tell us that some buildings had pitched roofs. Terracotta tiles with right angles indicate a water drainage system. Numerous loom weights are evidence of a textile industry.” By the later Bronze Age, Pavlopetri had morphed into the equivalent of Liverpool or Marseille today: a port city built around agriculture, trade, and fisheries.
Though Pavlopetri sank due to natural phenomena, its loss portends the threats coastal cities face from global warming today. Pavlopetri’s residents were among the first urbanites to experience the water’s force firsthand: they were forced to migrate — albeit gradually and quietly, as the city slowly disappeared into the ocean over centuries. By around 1000 B.C., a combination of earthquakes and sea level rise had sunk Pavlopetri completely.
Today, a visitor who reaches Vatika Bay might not notice any outward signs that a major historical site lies just beneath the surface. The beach of Pounta is a popular swimming place in summer. Euser says skippers of recreational boats often drop their anchors right on top of Pavlopetri’s ruins. Large commercial ships anchored in nearby Vatika Bay — some of which are involved in illegal hull-cleaning — generate pollution that threatens the site.
Members of the Greek chapter of ARCH are trying to combat this. They monitor the area with an app that maps near-real-time positions of ships and yachts worldwide, and regularly update a Facebook page called Ships Wreck Vatika Bay with posts that mention the exact coordinates of ships at anchor around the ruins. “The page aspires to witness the intentional destruction of Vatika Bay,” Euser says.
She also worries about people who are disrupting the site from the shore. Despite some small signs on the beach asking visitors to behave “tactfully,” tourists park their cars close to the shore and sleep inside the on-coast cist graves. Looting is also prevalent. Some visitors nonchalantly pick up bits of ancient stoneware and take them home, unaware of their potential historical value. I must have inadvertently engaged in antiquities smuggling myself. A pitch-black piece of granite rock that nature had conically carved into perfection, which I picked up from the beach, turned out to be a small piece of crockery — from a prehistoric household.
On this mild day in February 2022, I’m standing on the beach with Giannis Psarakis, the secretary and head of environmental protection at Toulipa Goulimyi, a nonprofit working to protect and promote the Laconia region’s natural and cultural heritage. Psarakis invites me to look closely at a pattern of rock-carved lines, which start where the beach meets higher ground west of Pounta, then slide seaward. “These lines continue underwater,” he says. “They stretch out to Elafonisos” — an island off the coast. The lines are ancient trade routes, negotiated by chariots when Elafonisos was united with the rest of Laconia in one landmass until a devastating earthquake in A.D. 375.
In recent years, the Greek government has taken steps to mark the area more effectively. The government published the boundaries of the Pavlopetri archaeological site in the Official Journal of Greece in 2018, and the site appeared on international marine charts later that year, says Euser. And in 2019, government agencies published a 40-page management master plan for Pavlopetri. Recommendations range from prohibiting parking and camping in the area to installing fences by the sand dunes to creating a visitors’ center.
Euser supports the plan but fears it has stalled, leaving the site vulnerable. “The Greek authorities have made no further efforts to protect or preserve Pavlopetri,” she argues. “COVID is often blamed.”
But Despina Koutsoumba, a maritime archaeologist at the Ministry of Culture’s underwater antiquities office, says the plan is moving forward on schedule. She also says some of the volunteers’ demands haven’t been realistic. “A while ago, we installed eight buoys — upon the insistence of Mrs. Euser,” says Koutsoumba, one of the master plan’s creators. “Half were swept away by current and half stolen — a waste of money.”
As global warming threatens modern coastal cities, there might be several fledgling Pavlopetris across the globe right now; parts of New Orleans, Venice, and Bangkok either lie below sea level or are sinking.
Last year marked the beginning of the United Nations Ocean Decade, an effort to ensure that ocean science helps countries achieve the U.N.’s sustainable development goals. Brian Helmuth, a professor of marine and environmental sciences at Northeastern University, says the attention to the threat of rising sea levels makes Pavlopetri more relevant today than ever. “It is a fantastic example of why we need to invest in ocean exploration. It is an amazing window into humanity’s past, when over 80 percent of the ocean remains a mystery to the human eye and less than 5 percent of the ocean floor has been mapped,” says Helmuth. “I would be shocked if there were no other sites like Pavlopetri that remain to be discovered.”
The drive to preserve sites like Pavlopetri also speaks to the ephemeral nature of cultures and ways of life — and the value of uncovering the past to better understand the present. Pavlopetri stands for thousands of years of human history compressed into one small site, protected by the sea. It is an immortalized time capsule that challenges a visitor’s perspective: on the ground floor of the capsule, you have the remains of the distant past; on the main floor, it’s you looking at the past. It’s highly possible that future humans will be looking at what you left from the upper floor 5,000 years from now.