Ancient monument was once a HUGE metropolis

The great medieval temple of Angkor Wat in Cambodia was once at the centre of a sprawling urban settlement, according to a new, detailed map of the area.

Using Nasa satellites, an international team have discovered at least 74 new temples and complex irrigation systems.

The map, published in the journal PNAS, extends the known settlement by 1000 sq km, about the size of Los Angeles.

Analysis also lends weight to the theory that Angkor's residents were architects of the city's demise.

"The large-scale city engineered its own downfall by disrupting its local environment by expanding continuously into the surrounding forests," said Damian Evans of the University of Sydney and one of the authors of the paper and map.

Working with researchers from Australia, Cambodia and France, the map was produced from ground surveys, airborne photography, and ground-sensing radar from Nasa's AIRSAR flying laboratory.