Ancient ruins hidden underneath a modern luxury hotel.

A Nesting Doll of Churches.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Rome’s legendary peephole vista is also a former Crusader stronghold.

A massive marble foot is tucked away in a small alley near the Pantheon.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

Roughly 17 million letters to Santa have found their way to this Arctic Circle post office.

The world's first and only escalator for lazy bicycles and their daunted riders.

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

Monuments don't get much more metal than these three giant viking swords planted in a Nordic hill.

The burning of this 12th-century church kicked off a campaign of Norwegian Black Metal terror.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

This "preacher's pulpit" once used for pagan ritual, is home to a new, and dangerous ritual.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

Eighty million natural history specimens call this gargantuan museum home.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

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

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A beautiful geyser under environmental threat.