A view of the ancient city of Petra January 4, 2008. Reuters/Muhammad Hamed

Google Earth and drones have helped in unearthing a massive ancient monument within the “lost city” of Petra in Jordan. It lay hidden in plain sight under the sand for thousands of years. The monument is twice as large as an Olympic-size swimming pool and nearly as long.

Petra is a well-surveyed archaeological site and quite a popular tourist destination. Details of the discovery of the huge manmade platform have been published in the Bulletin of the American Schools of Oriental Research. Petra has numerous monuments and tombs that were carved some 2,000 years ago by the Nabataeans. The discovery of this structure shows that there are significant historical structures that are still hidden and remain undiscovered.

The executive director of the Council of American Overseas Research Centers, Christopher A. Tuttle, has worked at Petra for around a decade. He collaborated with Sarah Parcak from the University of Alabama at Birmingham on the study. Tuttle said that many archaeologists like him have walked over this large monument for years never realising it was there.

“I’m sure that over the course of two centuries of research [in Petra], someone had to know [this site] was there, but it’s never been systematically studied or written up,” Tuttle told AP.

Different types of pottery were also found at the site. A second, smaller platform built on top of the first was also found. It was paved with flagstones and included a smaller structure on top. It is believed to include a doorstep.

Archaeologists have no plans of excavating the structure as there is a risk of damaging the site because of exposure to elements. However, without excavation, nothing much will be known about the structure. The platform may have been used for ceremonial purposes.

Petra was the capital of the Nabataean empire and also a thriving trade centre. However, many of the tombs were looted and destroyed by thieves, who also took away all the treasures. The city was lost to the world for hundreds of years and just sat empty. In 1985, Petra was declared a UNESCO World Heritage Site.

Petra's most famous building is the Treasury where scenes from “Indiana Jones and the Last Crusade” were filmed.