Archaeologists have discovered an ancient platform they say was "hiding in plain sight," just a stone's throw away from an iconic "Indiana Jones" filming location.

The massive platform was found using satellite images and drone photography of the Petra World Heritage site, in southern Jordan. The structure is about 56 metres wide by 49 metres long, with a smaller 8.5-metre-squared structure positioned on top of it. The site also shows evidence of a large staircase.

Petra is famous for the ornate building façades carved into the sides of its pink sandstone cliffs, in the style of ancient Greek architecture. One such façade was used in the filming of "Indiana Jones and the Last Crusade," as the exterior of the Temple of the Crescent Moon, the fictional resting place of the Holy Grail.

Sarah Parcak, of the University of Alabama at Birmingham, and Christopher A. Tuttle, of the Council of American Overseas Research Centers, published their findings in the May edition of the Bulletin of the American Schools of Oriental Research.

The study co-authors point out in their paper that Petra is visited by half a million tourists each year, yet many structures in the area remain undiscovered. "Even after two centuries of fieldwork in Petra and its environs, new discoveries and identifications of monumental structures continue to be made," they wrote.

The platform is believed to have been of ceremonial significance to the people of Petra, when the city was at the height of its power in the second century B.C. Archaeologists determined the site's age using pottery found nearby.