People have been living in the cave houses on this Italian hillside since the Neolithic era.

A dead saint, a deadly poison, and a mysterious holy ooze.

Southern Italy's spinning top village.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

Sleep where gangsters fell amidst smoke and flame, with nary a bullethole to show for the legendary struggle.

Sky ships, planes, and portraits left as unique tokens of hope and thankfulness.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Museum dedicated to the terror regimes of Hungary.

Once the home of a hermetic monk, this cave now houses a small church.

An abandoned Byzantine fortress and notorious prison.

Monasteries on rock pillars, once accessible only by frayed ropes.

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

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

A Nesting Doll of Churches.

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

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

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The neighborhood church casts a breast-shaped shadow that locals have come to call the “two o’clock titty.”

Alleyway plaque commemorating the death of a fictional character in The Maltese Falcon, not far from the author's home.

Golden Gate Park's historic collection of plants.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.