Australia's past had convicts transported from Britain, gold miners and outlaws; a 19th-century prison housed Sydney's most-dangerous criminals; a cave complex sheltered outlaws.

A history marked by conquest and conflict leaves a rich mythology of gods and men beneath the soil of Turkey; host Don Wildman investigates the truth behind legends of the Trojan War.

Host Don Wildman explores ancient structures buried beneath the desert sands of Egypt and the streets of Cairo, examines how these engineering marvels survived invasions, and discovers a tomb filled with 2,000-year-old mummies.

San Francisco is one of the nation's largest military defense installations with a huge underground ammunition depot, a former nuclear arsenal and Civil War fortifications buried under Alcatraz; human trafficking tunnels in Chinatown.

Christianity evolves in unique ways in Ethiopia's ancient underground engineering marvels and remote, cliffhanging caves; emperors' tombs; subterranean cathedrals; the Queen of Sheba's buried palace; possible site of the Ark of the Covenant.

Digging into the secret lives of ancient Roman gladiators, ranging from the depths of the Flavian amphitheater to a buried brothel where they lived their last days; host Don Wildman visits ancient crypts and chambers used for pagan worship.

Underground Los Angeles includes a haven for killer Charles Manson and his followers, tunnels where corrupt cops secretly ran the city, a dormant subway system, coastal military bunkers and war rooms ready for the next big quake.

Host Don Wildman tracks down subterranean secrets from Europe's Dark Ages, including a secret society's immense quarries, Templar torture chambers and the tunnels of medieval "ghost knights."

Host Don Wildman explores the trench systems and fortifications that made World War I one of the most brutal wars in history and helped shape Nazi Germany's Adolf Hitler.

Host Don Wildman explores the secret underground that helped transform Las Vegas from a barren desert into a mobster metropolis; underground vaults; secret surveillance nerve centers.

Host Don Wildman travels to Sicily to trace the Mafia's roots back to a vigilante secret society in an underground network that was created to put corrupt city officials on trial and execute the guilty.

Host Don Wildman discovers what it was like to live through World War II's Battle of Okinawa by exploring the Japanese defenders' tunnels, caves and bunkers; diving to a destroyer sunk off Okinawa's coast.

Don Wildman explores London, England, above and below ground to uncover its violent crimes, extreme poverty and lawlessness during the chaotic Victorian period.

Host Don Wildman digs into the subterranean world of Cold War secrets in Ukraine, where the former Soviet Union stockpiled nuclear weapons, established submarine bases and built underground apartment blocks.

Reminders of former Soviet leader Josef Stalin's terrifying legacy lie beneath the streets of Moscow in a subterranean web so vast that the Russian capital is in danger of caving in.

Exploring the top-secret underground defenses of Washington, D.C.; how the U.S. prepares for the worst possible scenarios, from a nuclear catastrophe to the ravages of disease.

Delving into Jerusalem's subterranean landscape uncovers an ancient escape route, a secret bullet factory, and data linked to the holy city's most-mysterious, most-enduring prophecies.

Technology beneath the streets of Tokyo is to protect the city from natural disasters; Hiroshima's underground affords shelter from World War II's most powerful bombs; the secret life of Japanese ninjas.

Exploring Vietnam War-era tunnels, passages and secret caves used as shelters; the massive Cu Chi tunnel system; superbunkers.

Evidence of the apocalypse is under the holy city of Jerusalem; host Don Wildman gains special access to a sacred stone said to protect the world from ultimate chaos.

Beneath the modern streets of Portland, Ore.