Archaeologists Sarah Parcak, a National Geographic fellow, and Christopher Tuttle, executive director of the Council of American Overseas Research Centers, used high-resolution satellite imagery followed by aerial drone photography and ground surveys to locate and document the structure.
They report that the monument is roughly as long as an Olympic-size swimming pool and twice as wide. It sits only about half a mile (800 meters) south of the center of the ancient city.
The enormous platform has no known parallels to any other structure in Petra.
The caravan city of Petra, in what is today southern Jordan, served as the capital of the Arab tribe known as the Nabataeans from its likely founding in the mid-second century B.C. The site was essentially abandoned at the end of the Byzantine period in the seventh century A.D.
Hundreds of thousands of tourists visit its iconic buildings, hewn from the local red sandstone, each year.