An abandoned 1970s theme park that has been turned into a space for waterfront walking.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

A botanically themed auditorium blooms within the world’s last operating double-decker theater.

A precariously balanced rock perches on the edge of a cliff created tens of thousands of years ago by glacial erosion.

This overlooked gem outside Niagara Falls preserves and celebrates Iroquois culture.

World's largest herd of white deer populate a former U.S. Army depot.

The rusting remains are visible sticking out of the waters of the Delaware Bay.

World War II bunker still standing on the New Jersey beach.

An amazing example of early-20th-century architecture, this church features marble transported from Utah.

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 grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

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

Also known as the Founding Church of Scientology.

A diminutive memorial marks the site of a successful assassination by a right-wing death squad in America's capital.

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

The school tested mustard gas for the U.S. Army during World War I.

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

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

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

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

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