The world's most incredible engineering projects are revisited to uncover why places full of mysteries and untold secrets are now abandoned ruins. S10 E1-Penthouse Palace S10 E2 - Castle Kingdom S10 E3 - Rock 'N' Roll Island S10 E4-K-Pop Dreamland S10 E5-The True Cross S10 E6-Blues Prison S10 E7 - Fake News Fortress S10 E8 - Turkish Wonderland