A vibrant, 100-foot-tall mural dedicated to Evelyn Nesbit, the tragic icon of the Gilded Age.

The Father of the Erie Canal has a magnificent grave marker that redefines the term "final resting place."

The last remaining 19th-century mile marker along the historic Ocean Parkway.

This sculptural piece by the artist Tom Otterness doubles as a jungle gym.

This museum dedicated to the history of the medical bone trade and human osteology.

Sip a cappuccino in the historic cafe that introduced them to the United States.

In 1986, Keith Haring was arrested for painting this anti-drug mural on a Harlem handball court.

A menagerie of concrete animals brought together from across New York City's parks.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

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

Largest Roman Catholic church in North America.

The United States Capitol's former columns still stand.

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

A super-sized promotional trick that is now a D.C. landmark.

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

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

A haunting tribute to pioneering photographer Clover Adams.

The most decorated dog of World War I is preserved in the Smithsonian.

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

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.