A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

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.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

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

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

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

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

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

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

A 200-year-old bar with a cheeky name claims to have served Edgar Allan Poe his final drink.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

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

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

A beloved horticultural oasis on the grounds of a wealthy family's former estate.

A somber memorial honors the hundreds of thousands of lives lost at this labor and extermination camp.

If it hadn't been caught in time, a flaw in the design of this Manhattan skyscraper could have led to its collapse.

These light, hollow rolls have been linked to Acadia National Park since the 1890s.

The first bridge observation tower in the U.S. offers one of the best views of Maine.