A former waterfront market is now in the center of town due to some interesting Boston engineering.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

The site of Paul Revere's historic two lantern warning.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

The Boston square dedicated to the dark poet who was born nearby.

The oldest house in Washington, D.C. wasn't originally constructed in the nation's capital.

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

The 28,000-year-old specimen is remarkably intact.

A line of blue paint marks the route of the inaugural parade.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

An overlooked memorial honoring the local Washington residents who died in World War I.

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

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

A much-maligned monument to teetotalism.

Washington's iconic carousel has a nice piece of Civil Rights history.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

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

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

Decades before the scandal, this staircase on the river was a literal "water gate."

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.