Giant naked man on a hillside.

The tallest hotel in Europe.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Where Nor'easters go to die.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

A stunning cemetery famous for its extraordinarily delicate & lifelike mourning sculptures.

Megachurch turned Catholic church comprised of 10,000 glass panes.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

Former headquarters of the KGB.

The clock that sets them all.

Elevated freight railway turned wildly successful urban park.

Tubing through a cave lit with glowworms is a magical underground experience.

Dynastic Home of the De Piro Family.

This communist country can still appreciate its fragrant past.

Large Hadron Collider and the Birthplace of World Wide Web.

Abandoned city hidden from the world by tropical forest and isolation on the coast of Kenya.

France's most famous cemetery, with some of its most curious tombs.

David Sedaris called it "The greatest shop in the world."

A spectacular cave and a beguiling lake.

The world's oldest known salt mine.

Hiding the longest subterranean river known in the world.

A fiery crater has been burning in the Karakum Desert since 1971.