A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

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

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

A winding, cliffside stretch of road overlooking the Delaware River.

This strange, big-tailed beast became a Pennsylvania town's unofficial mascot.

Legend says this sacred tree was a gift from goddess Athena.

The oldest standing Byzantine church in Athens is tucked within a monastery in the middle of an upscale shopping district.

A Byzantine-era church hidden in a wooded area below the Acropolis.

Where commuters walk through remnants of an ancient Greek necropolis.

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

An ancient octagonal weather station named for the eight Greek gods of wind.

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

A snapshot of the city's fascinating voodoo culture.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

High on a hill overlooking Los Angeles lives a world famous, high-power conical Tesla Coil.

Elevated freight railway turned wildly successful urban park.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

The first and only carousel with a lineup entirely of insects.

This historic building housed the surviving crew members of the Titanic, who were left destitute after the wreck.

One of the most enjoyable bits of history at Coney Island and “the most romantic ride in the world.”

This empty Victorian manse on Staten Island is said to be haunted but is actually a real life crime scene.