Mysteries of the Abandoned

Sea Fortress of Doom (2x8)

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A terrifying sea fortress, a highway in the Amazon that suddenly vanishes, and a mysterious structure in the shadow of the Statue of Liberty are deserted engineering projects; discoveries reveal how they were built and why they were abandoned. Stories: 1) Petrobras Viaduct, São Sebastião, Brazil; 2) Patarei Prison, Tallinn, Estonia; 3) Ellis Island, New York Bay, USA; 4) Ouvrage Restefond, Col de la Bonnette, France