The sprawling ruins of a once lavish destination are now mysteriously deserted in the mountains of Romania. Experts investigate and uncover the remains of the Herculane Spa, a luxurious spa resort and royal retreat entangled in a web of corruption.

A cluster of military defensive structures among a quaint holiday village lies deserted on a San Francisco Bay island; experts investigate and uncover a mysterious Civil War outpost on Angel Island that conceals a dark and hellish history.