With the assistance of data obtained in 2011 with advanced laser scanning technology, archaeologists have been able to identify the remains of a 1,700-year-old lost city on the island of Tongatapu in the Tonga island chain. Using the LiDAR remote sensing system, a popular tool for archaeologists performing aerial surveys, researchers spotted and mapped nearly 10,000 mounds upon which individual or family residences had been constructed in many cases, and where the buried tombs of elites had been located in others. These mounds were found distributed across the landscape about 7.5 miles (12 kilometers) away from Tonga’s capital city of  Nuku’alofa, along the island’s northern seacoast.

As of now, this is the oldest city ever found on an island in the southwest Pacific Ocean region. The site where the city was located is now occupied by a small, humble village known as Mu’a, which is actually a remnant of the ancient urban settlement that has survived to this day.

In a new reevaluation of the aerial data, plus an examination of further evidence collected during onsite excavations over the past several years, archaeologists Phillip Parton and Geoffrey Clark from the Australian National University in Canberra have revealed a host of new details about how and why this ancient city developed. They have also explained the greater significance of this urban settlement from the early first millennium, in the context of development patterns in the region as a whole.

LiDAR scanning has revealed the urban area that has been mapped. (Phillip Parton/ ANU)

Ancient Urbanization in the Pacific: An Unavoidable Adaptation

While the discovery of remains from an ancient city in any location is a cause for celebration among archaeologists, this find is both special and unusual. The Australian researchers say that this is likely one of the first cities to form on  any Pacific island, and its discovery shows that the people of Tonga were urbanizing much earlier than had previously been estimated.

“Earth structures were being constructed in Tongatapu around AD 300. This is 700 years earlier than previously thought,” Professor Parton told the Australian Broadcasting Corporation, commenting on dating procedures completed during archaeological fieldwork. He emphasized that this timeline meant urbanization in the Pacific had begun well before European contact took place, and therefore could not have been influenced by outsiders.

According to Parton and Clark, the ancient city represented an organic adaptation to growing population density on an island with limited space. It seems the architects of the city sought to urbanize at a pace that was as slow as possible, and the result was a settlement that was lower in density than modern cities, or even ancient ones in other parts of the world.

“Quantitative results show—for the first time—that settlements on a Pacific island were urbanized in a distinct low-density form and that the processes of urbanization began prior to state development,” the study authors wrote in a new article about their study appearing in the Journal of Archaeological Method and Theory.

LiDAR image of a mound neighborhood. (Phillip Parton/ ANU)

Using the latest methodologies for calculating ancient populations statistics, the Australian archaeologists believe that between 6,700 and 7,600 people lived at the ancient version of Mu’a, which was spread out over an area covering 2,900 acres (1,170 hectares).

“The settlement density at Mu‘a was 6.16 people per hectare, and the density of settlements [separate neighborhoods] larger than 100 hectares varied between 3.80 and 6.47,” they estimated in their journal article.

In comparison, the current capital of Tonga, Nukuʻalofa, has a population density of about 15 people per hectare.

Urbanization on ancient Tonga was not so much a preferred choice as it was a necessity, since space was far more limited than it would have been if the people were living on a vast continent. People couldn’t just migrate to wide-open spaces as population density grew, finding a way to live comfortably while more densely packed together was their only choice.

There is every reason to believe the same settlement patterns would have been recreated on other islands in the South Pacific, given the inherent limitations on living space that populations on all would have faced.

“As settlements grew, they had to come up with new ways of supporting that growing population,” Professor Parton explained. “This kind of set-up – what we call low-density urbanization – sets in motion huge social and economic change. People are interacting more and doing different kinds of work.”

True Tales of the Tongan Urban Innovators Revealed

The type of study just completed by the Australian archaeologists would have been difficult to undertake in the past. This was because of the difficulties of locating archaeological sites on island terrain, which is often mountainous or covered with thick forests. But the arrival of LiDAR, which stands for ‘light detection and ranging,’ has been a game-changer.

“We were able to combine high-tech mapping and archaeological fieldwork to understand what was happening in Tongatapu,” Professor Parton said. “Having this type of information really adds to our understanding of early Pacific societies.”

With respect to urbanization, the people of third and fourth century Tonga were true innovators.

“When people think of early cities they usually think of traditional old European cities with compact housing and windy cobblestone streets,” Professor Parton noted. “This is a very different kind of city.”

The ancient version of Mu’a featured open-sided houses built on top of mounds, which created a sense of privacy by separating residents from street-level activities going on below. The elevated height also provided residents with a view of the ocean, plus greater exposure to cooling sea breezes.

Throughout the city there were large open areas, which may have functioned like modern parks. The city was segregated by class, with elite homes and burial mounds protected from the rest of the population by gates and fortifications.  But regardless of where a resident of the ancient city lived, they would not have felt crowded or restricted in their ability to move about.

Ultimately, this style of urbanization did not survive on Tonga, nor anywhere else in the Pacific region. According to Professor Parton, this can be blamed on factors beyond the control of Pacific islanders.

“It didn’t collapse because the system was flawed; it had more to do with the arrival of Europeans and introduced diseases,” he said.

Now that so much has been learned about city building and architectural planning on the ancient islands of Tonga, the next step for archaeologists is to search for the ruins of undiscovered centuries-old cities on other Pacific islands. For his part, Professor Parton is confident that such ruins will eventually be found.

“This is just the beginning in terms of early Pacific settlements,” he said. There’s likely still much to be discovered.”

Top image: Earth structures were being constructed on Tongatapu around AD 300. Source: Phillip Parton/ANU