A church of bones, decorated with 40,000 human skeletons.

One of only two commuter aerial tramways in the United States.

360° views of the city plus five floors of optical illusions and hands-on science.

Elevated freight railway turned wildly successful urban park.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

A terrific purveyor of natural history objects and curios.

World's first "penitentiary," meant to be humane, drove men insane.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This once-derelict building is now one of the most beautiful bookstores in the world.

In this Parisian garden's grotesque former life as a zoo it fed exotic animals to the bourgeois and put humans on exhibit.

It's believed that these columns marked the end of the Via Appia.