Poompuhar Beneath the Bay of Bengal: The Sangam Port City Lost to a 3rd-Century Tsunami

For centuries, the ancient port city of Poompuhar existed only in the lyrical stanzas of Tamil Sangam literature. Poets spoke of a metropolis so grand that its towering mansions “touched the clouds” and its warehouses overflowed with gold from Rome, pearls from the southern ocean, and sandalwood from western mountains. Then, according to the epic Silappadikaram, the city was “swallowed by the sea” in a single cataclysmic event—a divine punishment for a king who forgot to honor the god Indra.

What was dismissed for nearly two millennia as mythological exaggeration is now being validated by marine archaeologists. Between September 2024 and October 2025, the Tamil Nadu State Department of Archaeology (TNSDA) conducted the most advanced underwater survey of the Poompuhar coast since the 1990s, and the findings are rewriting the maritime history of early South India.

The City That Sangam Poets Built

Before discussing what lies beneath the waves, we must understand what stood above them. Poompuhar—known variously as Kaveripoompattinam, Puhar, and Kaveripattinam—was the early Chola dynasty’s premier port capital. Located at the precise point where the Kaveri River meets the Bay of Bengal (Lat. 11° 08′ 33″ N, Long. 79° 51′ 31″ E), the city occupied a strategic position that made it the hub of transoceanic trade routes connecting Southeast Asia to the Roman Empire.

The Pattinappalai, a long poem from the Pattupattu anthology dating to approximately 100 BCE–100 CE, offers the most vivid surviving description of the city. Written by the poet Uruthirankannanar in praise of the Chola king Karikala, the poem describes a metropolis of staggering prosperity. “Swift horses with lifted heads arrive on ships from abroad,” the poet writes. “Sacks of black pepper arrive from inland by wagons, gold comes from northern mountains, sandalwood and akil wood come from the western mountains, and pearls come from the southern ocean”.

The city was not merely a trading post but a planned urban center. Silappadikaram records that Poompuhar sprawled across approximately 30 square miles, encompassing 30 villages and housing an estimated 60,000 families. The city was divided into distinct quarters: the Maruvurpakkam, where fishermen and weavers lived; and the Pattinappakkam, the elite mercantile district where foreign traders—including Yavanas (Greeks and Romans)—had their own enclaves. Read Untold Story of Trade Between the Tamil Country and the Roman Empire

The Akananuru describes the city’s skyline as nearly surreal: “Kaveripoompattinam with streets with forts that touch the sky that appears like the top side of a fish, fine houses are tall and their tops cannot be seen”. Archaeological excavations on land have corroborated these descriptions, revealing brick structures, terracotta ring wells, and storage jars consistent with the Sangam period (3rd century BCE to 3rd century CE).

The Deluge: Separating Myth from Geology

The Silappadikaram narrates the city’s destruction with tragic finality. A Chola king, overcome by grief at the death of his son, neglects to celebrate the annual Indra Vizha festival. The goddess Manimekhala, enraged by this omission, curses the city: “Let the beautiful city be destroyed by the sea.” The epic records the aftermath starkly: “Puhar was ruined. As the sea flowed over the large city… the king departed from thence all alone, uprising waves engulfing noble Puhar”.

For generations, scholars interpreted this as poetic allegory. But geological and marine archaeological evidence has since revealed a different story—one where a natural disaster, not divine wrath, erased the city.

The Tamil language contains specific words for such cataclysmic events: Kadalkol (sea inundation), Peralai (great wave), and Oozhi (deluge). Sri Lankan historical records document three major Kadalkol events: one in 2378 BCE, another in 503 BCE, and a third in 306 BCE. The 2004 Indian Ocean tsunami, which devastated the same coastline, demonstrated exactly how such a disaster could overwhelm a coastal metropolis.

Marine geologists studying the Poompuhar coastline have identified several contributing factors to the city’s submergence. The sea level has risen approximately 1 mm per year over the past two millennia, resulting in a net 2-meter rise over 2,000 years. Given the gentle gradient of the near-shore bathymetry—as shallow as 1 meter per several hundred meters of coastline—even this modest rise would have submerged significant portions of the coastal plain. The 2004 tsunami, which inundated up to 500 meters inland along this same coast, provided a modern analog for what may have occurred in the 3rd century BCE.

The northeast monsoon season brings cyclones that dramatically accelerate coastal erosion. Each major cyclone permanently removes beach sediment, with the volume of sediment transport increasing considerably during these short, violent spells. Over centuries, this process would have progressively consumed the shoreline upon which Poompuhar stood.

The scientific consensus now points to a tsunami occurring sometime during the 3rd century BCE as the final blow that “swallowed” the remaining portions of the city.

What Lies Beneath: Decades of Underwater Discovery

The first systematic underwater explorations off the Poompuhar coast began in the 1970s, but it was the National Institute of Oceanography’s surveys in the late 1980s and 1990s that produced the first incontrovertible evidence of a submerged city. Between 1989 and the early 1990s, marine archaeologists used side-scan sonar, echo-sounders, and magnetometers to map the seabed off Tranquebar and Poompuhar. What they found was astonishing.

In the intertidal zone—the area exposed at low tide—divers discovered terracotta ring wells of a type identical to those used in Sangam-era habitations. Each ring measured approximately 75 cm in diameter, 15 cm in height, and 6 cm in thickness. These were not isolated finds; entire clusters of ring wells appeared along a 300-meter stretch of the intertidal zone near Vanagiri, south of the Yellaiyamman temple.

Brick structures, some extending 25 meters in length and 3.4 meters in width with bricks measuring 22x13x6 cm, were documented approximately 60 meters from the high-water line at a depth of just 1 meter. The brick dimensions closely match those found at the Buddha Vihar in Kaveripattinam, securely dating them to the Sangam period.

Perhaps most compelling was the discovery of a neatly paved brick floor—likely the floor of a house—exposed in an intertidal excavation. Adjacent to this floor, a terracotta ring well surrounded by burnt bricks yielded megalithic black-and-red ware pottery, beads of semi-precious stones (including agate, crystal, carnelian), glass beads, and most significantly, a potsherd inscribed with the Brahmi letter “Ma”.

Copper coins bearing the tiger emblem of the Cholas—the same “potent tiger mark” described in Pattinappalai—have been recovered from both intertidal and offshore contexts. Later Chola coins have also been found, suggesting that attempts were made to reoccupy or rebuild on the site after the initial submergence.

Offshore, in deeper waters, divers located well-dressed stone blocks, including one semi-circular in shape, suggesting that stone was also used for monumental architecture. However, brick structures—the primary building material of the Sangam period—are less likely to survive intact in the high-energy zone beyond 8-9 meters depth, where waves and currents would have reduced them to rubble centuries ago.

A comprehensive 1991 survey by the National Institute of Oceanography concluded that “a township was submerged between Tranquebar and Poompuhar” and that “one or two wrecks lie buried” in the seabed. Airlift operations revealed that habitation deposits were buried at least 1 meter below the current sediment level, with ceramic evidence placing the occupation firmly in the early centuries of the Christian era.

2024–2025: New Technology, New Discoveries

After more than two decades without systematic underwater exploration, the Tamil Nadu State Department of Archaeology launched a major new survey off the Poompuhar coast in September 2024. The timing was strategic: the Tamil Nadu Budget for 2025-26, presented by Finance Minister Thangam Thennarasu, had specifically allocated resources for “deep-sea excavations between Poompuhar and Nagapattinam” to uncover the state’s maritime heritage.

The 2024 survey, led by a team of 10 divers including experts from the Indian Maritime University, employed an array of advanced technologies that were unavailable to researchers in the 1990s. These included remotely operated vehicles (ROVs), side-scan sonar, multibeam echo sounders, and sub-bottom profilers—instruments capable of penetrating the seabed to reveal buried structures without excavation.

A subsequent 2025 study published in the Journal of Engineering Science and Technology detailed the technical methodology used in these surveys. The research team deployed Multibeam Echo Sounders (MBES) with a 400 kHz central frequency, capable of generating high-quality bathymetric maps of the seafloor. The MBES system transmitted sound beams narrow in the along-track direction, with the signal processor applying Automatic Gain Control (AGC) to eliminate large-scale effects of angle of incidence and Time Variation Control (TVG) to create uniform display of sonar data across varying distances.

The sub-bottom profiler proved particularly valuable, producing 2D and 3D images of features buried up to 70 meters below the seabed. These images revealed “aligned crests, seemingly composed of sand and flat areas, suspected to be sand-mud” that correspond to the textural patterns of submerged structures. The research team specifically cited the identification of “submerged land area in Poompuhar” in their processed images.

The 2025 phase of the survey, conducted over 12 days in September and October, focused on the stretch between Thirumullaivasal and Neithavasal. The TNSDA team, led by Joint Director R. Sivanantham, traced several underwater locations previously identified by veteran archaeologist S. R. Rao during his surveys in the 1990s. Using side-scan sonar and ROVs, the team mapped the seabed to a depth of 23 meters and documented structural anomalies that may represent additional architectural remains.

Data analysis from both survey phases is currently underway, with the TNSDA planning an additional exploration phase when sea conditions next favor underwater visibility—typically during the calm pre-monsoon months when sunlight penetrates deeper and surface turbulence is minimized.

The Kumari Kandam Connection

The story of Poompuhar is inextricably linked to one of Tamil culture’s most enduring and controversial legends: Kumari Kandam, the mythical lost continent said to have extended south of Kanyakumari. Ancient Tamil Sangam texts speak of a vast landmass that was repeatedly swallowed by the sea in a series of cataclysmic deluges, forcing the migration of Tamil peoples to what is now modern-day South India.

Sangam traditions record that the first two Tamil Sangams (literary academies) were held in cities that were subsequently submerged by the sea. Only the third Sangam, held in present-day Madurai, survived. The works of the first two Sangams, along with the cities that housed them, were lost forever beneath the waves.

While mainstream archaeology does not accept the existence of a continent-sized “Kumari Kandam,” the Poompuhar discoveries have lent credence to the smaller claim: that significant coastal settlements did indeed vanish beneath the Bay of Bengal due to sea-level rise, tsunamis, and coastal erosion. The description in Manimekhalai that earlier Poompuhar was located some 17 kilometers inside the current Bay of Bengal aligns remarkably well with marine geological evidence of shoreline retreat.

Tamil Nadu State Department of Archaeology officials have been measured in their interpretation. Finance Minister Thennarasu stated upon launching the 2024 survey that “the history of Tamils will now be explored even beneath the sea,” highlighting the survey’s role in “rediscovering and studying the antiquity of ancient Tamil civilization”—without making specific claims about lost continents.

Preservation Challenges and Future Prospects

The submerged remains of Poompuhar face ongoing threats from the same forces that destroyed the city: cyclones, erosion, and rising sea levels. The 2004 tsunami, which caused extensive damage along the Tamil Nadu coast, also altered seabed topography and may have disturbed or reburied archaeological deposits.

The Masilamani temple at Tranquebar, approximately 15 kilometers south of Poompuhar, offers a sobering lesson in coastal vulnerability. This 10th-century Chola temple, originally built at a safe distance from the sea, has lost more than half its structure to encroaching waves. The remains of a Dutch fort in the same area are now entirely submerged, visible only at low tide.

The TNSDA’s 2025 survey was deliberately scheduled for September and October, the period of least sea roughness on the east coast, and operations were restricted to 10 a.m. to 3 p.m. to maximize underwater visibility. The team used small fiber boats launched from larger mechanized vessels to access precise survey points, with local fishermen providing crucial logistical support.

Future exploration will likely focus on deeper waters beyond the 23-meter depth limit of the 2025 survey, using more sophisticated ROVs and possibly autonomous underwater vehicles (AUVs) capable of longer endurance missions. The Department of Science and Technology has expressed interest in digitally reconstructing Poompuhar based on the combined data from sonar surveys, seabed drilling, and remote-sensing geodynamic studies.

Such a digital reconstruction would allow researchers and the public to “walk” through the streets of Poompuhar as described in Pattinappalai—past the warehouses sealed with the Chola tiger emblem, past the monasteries where sages performed rituals, past the bustling wharves where Roman ships unloaded their cargoes of wine and gold.

Poompuhar Myth Confirmed, History Rewritten

The story of Poompuhar occupies a unique space in South Asian archaeology—a convergence of poetic literature, geological science, and underwater exploration. What began as a “mythical” city dismissed by 19th-century historians has emerged as a historical reality, confirmed by decades of patient archaeological work beneath the challenging waters of the Bay of Bengal.

The 3rd-century BCE tsunami that destroyed Poompuhar was not divine punishment but a natural catastrophe—one that the 2004 Indian Ocean tsunami demonstrated could happen again. Yet in its destruction, the sea preserved what the land could not. The ring wells, brick structures, storage jars, and coins that lie scattered across the seabed offer a time capsule of early Chola civilization, frozen at the moment of its greatest prosperity.

As the TNSDA prepares for its next phase of exploration and the digital reconstruction of the city takes shape, one fact has become inescapable: Poompuhar was not a poet’s fantasy. It was a real city, of real people, who built a maritime empire that linked the Tamil country to the wider world. And it waits, still, beneath the waves, for technology to fully reveal its secrets.

Bibliography

1. Times Now. (2020). “Researchers digitally recreating lost city of Chola dynasty: In search of the lost ports of Tamil Nadu.” 

2. Palaniammal, P. (2023). “Historical Analysis of Poompuhar Submergence.” Government Arts College, Salem. Zenodo.

3. Sasilatha, T., Immanuel, T.B., & Kumar, M.A. (2024). “A Case Study on Underwater Structural Data Processing Towards Digital Recreation of Poompuhar – Heritage Landmark in South India.” Journal of Engineering Science and Technology, Special Issue on ICIT2022, 19(2), 89-96.

4. The Hindu. (2025, October 20). “TNSDA completes the first phase of underwater survey off the Poompuhar coast.“

5. Sundaresh, Jaya Kumar, S., & Sanil Kumar, V. (2006). “Shoreline Changes along the Poompuhar Tranquebar Region.” In A.S. Gaur & K.H. Vora (Eds.), Glimpses of Marine Archaeology in India. Society for Marine Archaeology. National Institute of Oceanography. 

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