A priceless collection of the Nation's cryptologic history.

The prototype for all Nazi concentration camps.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

World's first "penitentiary," meant to be humane, drove men insane.

Art deco landmark on the outskirts of Washington, D.C.

Largest Roman Catholic church in North America.

Bar full of oddities, specimens, artifacts and homages to the great dime museums of the past.

The United States Capitol's former columns still stand.

Where monkeys run wild and the humans are caged.

Daily lunch spot for many of Washington, D.C.'s cab drivers.

At 207 feet, one of the world's longest continuous escalators.

The hidden jewel of Disneyland: a members only playground for the Disney elite.

340-foot statue built to honour the Heroes of the Soviet Union.

Frida Kahlo's childhood home, now a museum of her life and works.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

Golden Gate Park's historic collection of plants.

Former villa and estate of James Deering developed to preserve native tropical forests.

There just so happens to be a court even higher than the U.S Supreme Court: a basketball court in the building itself.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

Hear the quietest sound from across the dome.

This elephant kraal is the only one remaining in Thailand, dating back to the 16th century when these massive mammals were integral players in war and trade.

A 200-year-old bar in the historic French Quarter refuses to give up its place in history, nor its role in securing ours.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.