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

A colorful square marks the heart of the city's LGBTQ community.

This bronze sculpture was inspired by a photograph of Martin Luther King Jr. and his wife embracing after he won the Nobel Peace Prize.

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

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

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

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

This Asian-inspired tower in a lush urban park provides spectacular panoramic views of Baltimore.

Once America's tallest structure, now a Baltimore landmark.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

An abandoned church gets a second life as a massive beer hall and event space.

A museum dedicated to exhibiting remarkable outsider art.

This beloved Baltimore spot features caged dolls, a giant Pez collection, and many, many mannequins.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

The small first-floor apartment where the author wrote her Pulitzer Prize-winning book 'Gone with the Wind.'

The name of this tiny pocket park tucked between two buildings on Manhattan's Upper West Side is Latin for its location: "seventy-one."

A disquieting Aztec sculpture displays hundreds of stone skulls representing the victims of human sacrifice.

Deep scars on the earth left by the Ice Age.

A touching tribute to the "Queen of Soul."

One of the remaining markers of an era when Brooklyn and Flatbush were separate cities.

This hidden oasis features a stunning view of the Hudson River and the Palisades from a castle-like museum.

A B.Y.O.B. Mexican cantina lives inside one of the last tortilla factories in Brooklyn.

A once grand hotel is being retaken by the wilderness it once capitalized on.

This massive melon is a recreation of a similar gate from the Pan-American Expo.