This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

The Kirkland Monument remembers a selfless Civil War hero who braved the battlefield to give water to his dying enemies.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

A girls' boarding school inspired by the Chicago World's Fair, once abandoned, now restored to strange and scenic glory.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

An interesting decoration on this historic site, this weathervane comes with as many legends as it does questions.

Diego Rivera's massive tiled fountain and failed infrastructure project.

Frida Kahlo's childhood home, now a museum of her life and works.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

There aren't too many operational funiculars around, but Pittsburgh has two!

Love, knishes, and best wishes from this legendary Lower East Side bakery.

The body of St. John Neumann and his collection of hundreds of relics, on display in a Philly church.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

The world’s first penitentiary, meant to be humane, drove men insane.

The Corinthian columns that towered over Abraham Lincoln’s inauguration stand proud.

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.

This modern castle sat empty for decades before a fire inspired its builders to complete its luxury halls.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The largest cemetery in Louisville is the final resting place of Col. Sanders and Muhammad Ali.

The world's longest known cave system.

Prehistoric animals decorate this popular outdoor park.

This huge clock made of flowers and simple machinery was once used a political weapon.