This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

Once a strategically imperative naval base, portions of this Bermuda dock complex now serve cruise ships.

The world's smallest drawbridge.

Where a rare geological phenomenon created a section of rock that resembles a checkerboard.

This distinctive Crescent City tradition dates back to the days of horse-drawn carriages.

The world-record holder for the longest bridge stretching continuously over water.

The second oldest continuously operating bar in Louisiana.

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

Dedicated to the man who created the first radio wave communication system.

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

A gift from Japan, 17th-century lantern stands among the cherry trees at D.C.'s Tidal Basin.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

One of the three perfect vellum copies of this historic book known to exist is on display in a specially-designed case.

The only Leonardo Da Vinci painting in the Western Hemisphere.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

The National Park Service’s best-kept secret with views that rival any in D.C.

This forgotten boat elevator was an engineering marvel in its heyday.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

Look closely and you’ll notice that the color changes a third of the way up the tower.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

The "lovely red Vega" of the legendary record-settling pilot.

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.