Mysteries of the Abandoned

They were once some of the most advanced structures and facilities on the planet, standing at the cutting-edge of design and construction. Today they are abandoned, dangerous, some of them even deadly. From uninhabited cities to empty factories, these long-forgotten engineering marvels are scattered around the globe. Science Channel uncovers why some of the world's most advanced architectural achievements were eventually left behind in the all-new series Mysteries of the Abandoned.