A lost Cambodian city that predates the renowned Angkor Wat temple complex by centuries has been discovered in the jungles along a mountainside in the country's northwest.

Previously undocumented evidence of temples, ancient canals and rivers, dikes and roads were found by combining the latest in data gathering technology with Indiana Jones-style archeology. The find amounts to a hidden city that predates the renowned Angkor Wat temple complex by 350 years.

Cobbling together pieces of evidence - a stone altar here, evidence of an ancient road there - creates a more complete picture of the ancient city: Mahendraparvata, a lost medieval city where people lived on a mist-shrouded mountain called Phnom Kulen, during the Hindu-Buddhist Khmer Empire that ruled much of Southeast Asia from about 800 to 1400 A.D., during a time that coincided with Europe's Middle Ages.

GPS and lidar data guided Damian Evans, the director of the University of Sydney's archaeological research center in Cambodia, and his team to the individual ancient ruins, sometimes buried beneath thick overgrowth in an area peppered with landmines from more recent war.

It is not yet known how large Mahendraparvata was, as the GPS and lidar data are not yet complete. Lidar - or light-detection and ranging data - is responsible for several great archaeological finds, including the 2009 discovery of extensive terraced farming networks in the Mayan city of Caracol, and a recent expedition at Stonehenge, Australian newspaper The Age reports.

The lidar system effectively peeled away the jungle canopy, allowing the researchers to see perfect square structures and evidence of a network or roads and dikes, which allowed them to complete a map of the ancient lost city. Surprisingly, much of the city, though in ruins, was not compromised over the centuries. On the ground archaeologists found little of the telltale signs of looting.

Despite 1,200 villagers living in the area around the newly found ruins, none of them realized they were living in the middle of the ancient city.

Evans offered a hypothesis on the ancient city's demise: "One theory we are looking at is that the severe environmental impact of deforestation and the dependence on water management led to the demise of the civilization ... perhaps it became too successful to the point of becoming unmanageable," Evans told the journalist Lindsay Murdoch, the Southeast Asia correspondent Fairfax Media, whose piece ran in The Age and The Sydney Morning Herald.

"Maybe what we are seeing was not the central part of the city, so there is a lot of work to be done to discover the extent of this civilization," Evans said.

The discovery is set to be published in the journal Proceedings of the National Academy of Sciences in the United States.