What Lies Beneath D.C.

Prepare to see a dark side of the nation's capital -- one that doesn't involve politicking or hotel rendezvous.

History's "Cities of the Underworld" series travels to the District this week, taking viewers to places ordinarily far beyond -- or below -- their notice. The episode begins in the black of night with host Don Wildman dropping into a manhole at an undisclosed location to explore the extensive sewer tunnels that run under the city.

The tunnels were created in the 19th century when Tiber Creek, along present-day Constitution Avenue, was diverted underground because it had become rancid with sewage. The system "is actually kind of beautiful," Wildman said.

Being led through the tunnels by a D.C. Water and Sewer Authority employee was impressive, Wildman said, given the security that protects the places above them. "It was pretty wild to be within a stone's throw of the Capitol at 3 a.m.," he said.

Other regional attractions Wildman visits in this episode:

nA now-defunct fallout shelter at West Virginia's posh Greenbrier resort that would have housed top political figures in a nuclear attack.

nBaltimore's Fort McHenry, whose de-sign included underground features meant to prevent a catastrophic munitions explosion.

nWest Virginia's Organ Cave, a geological wonder that housed a factory providing the Confederacy with much of its gunpowder during the Civil War.

Wildman, a self-described "American history nut," said he's always awed by what's underneath the cities he profiles, including the District. "There's no underground in the world that doesn't have a story to tell," he said.

-- Becky Krystal

CITIES OF THE UNDERWORLD

Monday

9 p.m., History