Cryptic messages embedded in the New York City sidewalk.

The origins of midtown Manhattan's anachronistic wooden farmhouse remain a mystery.

Elevated freight railway turned wildly successful urban park.

The only remaining building in New York to see the inauguration of a president is being slowly overtaken by a grocery store.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

Constructed in the 1920s, this former pencil factory is now an office building.

The most loyal of little dogs, or a Victorian era publicity stunt?

A blooming house of worship for the masses.

World's most expensive home.

An extraordinary "City of Caves" carved from solid stone.

The remains of what was, not so long ago, the world's largest city.

Scholar, adventurer, saint, and instigator of the Goa Inquisition.

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

The 953 windows undoubtedly make this the world's most beautiful screened porch.

Sacred Indian temple that’s all monkey business.

Go inside to really appreciate this 500-year-old technological masterpiece.

The world's second-largest sundial, made entirely out of stone.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Replicas of Apollo's leonine stone guard cats still line a sacred row in Greece.

This famous archeological mystery may be an ancient example of movable type.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

A Bronze age settlement on the Greek island of Santorini might have been the inspiration for Plato's Atlantis.

A 200-year-old collection of oddities and medical paraphernalia.

This stately monument has been wearing a traffic cone hat for decades much to the delight of the locals.