第 4 季 共 9 集
播出时间：2019年4月5日
第 1 集 World's Strangest Ghost Towns
播出时间：2019年4月5日
The world's strangest ghost towns are home to dark secrets, creepy buildings and eerie sights; new discoveries reveal why they were abandoned.
第 2 集 Secret of Supervillain Island
播出时间：2019年4月12日
On a strange island off the coast of Croatia, the mysterious ruins of a long-abandoned hideout look like they once belonged to a James Bond super-villain, and new discoveries reveal why it was built and why they were abandoned.
第 3 集 Escobar's Castle
播出时间：2019年4月19日
The ruins of a once-palatial compound contain the secrets of one of history's most notorious criminals, and new discoveries reveal why this high-security estate was built and why it was abandoned.
第 4 集 Labyrinth of the Dead
播出时间：2019年4月26日
Tunnels filled with human bones lie beneath the streets of Paris, and this horrifying engineering marvel points to a dark secret; new discoveries reveal why this grisly underground death maze was built and why it was abandoned.
第 5 集 Treasure of Outlaw Valley
播出时间：2019年5月3日
A ghost town in the American West was once a Gold Rush hotspot and one of the most violent places in America. Today, there are legends of a secret treasure buried in the surrounding hills, and new discoveries might finally reveal its true location.
第 6 集 Alaska's Fort Apocalypse
播出时间：2019年5月10日
In Alaska, the ruins of a massive compound point to eerie evidence of an apocalyptic mystery. New discoveries reveal why this strange marvel was built in the snowy wilds of the Last Frontier and why it was abandoned.
第 7 集 Alien Hell Portal
播出时间：2019年5月17日
A strange complex of tunnels on the grounds of a bizarre mansion were under lock-and-key for a century. Since its rediscovery, some believe its mysterious place is a gate to hell. New discoveries reveal its secret purpose and why it was abandoned.
第 8 集 Pompeii's Gate To Hell
播出时间：2019年5月24日
Near the destroyed city of Pompeii, an eerie complex of underground tunnels snake beneath a volcano, and some believe these passages were intended as a gateway to hell. New discoveries reveal exactly why they were built and why they were abandoned.
第 9 集 Haunting on Plague Island
播出时间：2019年5月31日
A strange complex of buildings on a remote tropical island was once home to a large seaside community, but today, locals avoid the area and claim that it's haunted. New discoveries reveal why this eerie place was built and why it was abandoned.
