The history of Cambodia’s defining landmark is being transformed following groundbreaking archaeological discoveries, according to researchers from a major international collaboration at Angkor Wat.

The revelations, published this week, are the fruits of the latest phase in the five-year-old Greater Angkor Project, which has employed multiple airborne laser scans alongside ground-penetrating radar and targeted excavation to map the immense preindustrial temple complex.

Headed by a team from the University of Sydney and supervised by the Apsara Authority, it has revealed the site is two-thirds larger than formerly supposed and encompasses multiple unmapped components, including a mysterious new structure of spirals spanning some 1,500 metres by 600 metres.

“[This] is the most striking discovery associated with Angkor Wat to date,” said professor Roland Fletcher, project co-leader from the university’s Department of Archaeology, adding that tourists and researchers have unwittingly been walking across the featureless heaps of sand for the past century.

“Its function remains unknown and, as yet, it has no known equivalent in the Angkorian world,” he says, though he noted a hypothesis that the spirals might have fed water into gardens around Angkor.

The findings confirmed researchers’ contention that Angkor Wat was a major temple within a residential city of some 750,000 people, rather than a sacred precinct of temple cities.

They also revealed the complex wasn’t merely the domain of religious or ruling elites, but included laypeople and workers living in domestic housing.

“This challenges our traditional understanding of the social hierarchy of the Angkor Wat community,” Fletcher explains.

So too, a discovery that Angkor was fortified with seemingly defensive structures late in its history poses further questions about a landmark with no historical record.

“There is essentially no textual history, so it is archaeology revealing what happened,” he explains, noting that the team’s next step will be dating the new structures.

According to the Apsara Authority who oversees the site, the novel discoveries reflect a challenge as well as an opportunity.

“This is both very surprising and very fascinating, but the first step will be to verify the findings,” says Long Kosal, Apsara’s deputy director of communication, adding that the project was helping to recover lost history.