What on Earth?

Secrets of Lost Cities (2x8)

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while a satellite takes photos of western Brazil a cleared part of the jungle shows signs of ancient construction that may be the fabled City of Gold, El Dorado; radar images of the empty quarter of Oman show tracks or roads that may lead to Ubar, the mythical 'Atlantis of the Sands'; amateur archeologist search satellite images for ancient walls in Northern California that have the potential to rewrite American history; a 50 years old satellite image shows a winding channel cut into the desert of northern Iraq that may lead to the site of the ancient Hanging Gardens of Babylon; archeologists using aerial photography discover what may be an ancient sunken city off the coast of Wales which some believe may be evidence of an ancient kingdom known as The Lowland Hundred; in 2011 a mysterious structure is seen in the Lybian desert could it have been built by Romans or someone else