Don penetrates a former Nazi military compound, uncovers clandestine oil rigs in seemingly normal neighborhoods, and kayaks down the LA River revealing a rarely seen side of Los Angeles.

520 feet above Seattle, Don Wildman experiences the Emerald City from the outer rim of the Space Needle. Mosquito Fleet steamboats prove difficult to find in the icy waters surrounding the city.

Don goes to Oak Knoll Naval Hospital and an old WWII POW camp.

The host visits Arizona and checks out a secret missile silo and a lost gold mine.

Don goes rafting in Tennessee and checks out a secret moonshine operation. Also: a look at collapsing coal mines and prehistoric caves.

Don visits an old powerhouse in Buffalo. Later, he checks out a tunnel system from the early 1800s.

Don gets access to an isolated stronghold that once saved New York city, uncovers the fantasy island arsenal of the biggest arms dealer on earth, and scrambles around a forgotten relic once used to keep the depraved out of site.

Don explores Boston to uncover how this city has solved big problems with bold ideas -- from the first subway in the US to a waste treatment plant that helped clean up the infamous mess in it's harbor.

Don explores the hidden corners of New York City.

In Hawaii, the host explores a hi-tech tunnel bored into a volcano. He also uncovers secret bunkers and learns about ancient bloody rituals.

The host visits St. Louis and explores the city's willingness to embrace change through the years.

Don explores Pittsburgh's industrial wasteland and hi-tech wonders.

Don explores the Twin Cities of Minneapolis and Saint Paul, Minnesota, revealing the secret past of these sibling cities and their hidden underworlds.

In the second season premiere, host Don Wildman blasts and pours gold, visits Alcatraz in San Francisco to retrace the infamous escape route, takes part in a parade in Los Angeles, California, makes whiskey barrels in Kentucky, and explores an engineering marvel.

Wildman wrestles alligators in Florida, pilots the world-famous Good Year Blimp in Ohio, goes underground zip-lining in Louisville, Kentucky, and explores seismic engineering in San Francisco, California.

The host tests fireworks in California, helps build jet engines in North Carolina, and carves stone for the Washington National Cathedral.

A futuristic array of luggage conveyors; a manned rover designed for exploration of other planets.

Toughest work environments, including fighting fires, cleaning up waterways and repairing an Olympic venue.

Grand Central Station in New York City; class four rapids; a port that ships out scrap metal.

Gator wrestling; NASCAR pit crews; a Las Vegas show; the Goodyear Blimp.