100 years later, they're still down there.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

The tunnel under the Capitol Building where Congress takes out its trash.

The Pentagon is so large that it was planned like a city, complete with internal highway infrastructure.

A bike being "eaten" by a tree is the real Vashon legend behind popular children's book, "Red Ranger Came Calling."

Bonsai trees that are up to a thousand years old.

The center of the only hemisphere that awards visitors with a commemorative coin.

Beautiful Gothic-inspired lighthouse stands out among the run-of-the-mill striped fare on Bodies Island.

A museum dedicated exclusively to aircraft used in the military.

A remarkable time capsule of American manufacturing deep in Maryland coal country.

Every drop of D.C. tap water flows through this old waterworks.

These abandoned waterworks are crumbling into the Potomac River.

An ancient iron pillar in Delhi that seems to be rustproof.

Light still pours into the ruins of this ancient Islamic observatory.

The second-largest gold nugget in existence, displayed in a Las Vegas casino conveniently named the Golden Nugget.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

Brightly colored 30-foot-tall totems light up the desert sky just outside Las Vegas.

A new kind of theme park for adults off the Las Vegas Strip.

An exotic wildlife habitat right off The Strip.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

Some cheeky plantings brighten an old slipway on Scotland's Firth of Forth.

The grand, column-fronted, sculpture-adorned home of the ambitious digital library.

The old Route 66 town straddling Texas and New Mexico died along with the Main Street of America.

This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.