This building displays the scars of the “Dekemvriana,” a dark time in modern Greek history.

These ancient ruins hide in plain sight next to a dessert shop.

These caves secretly held national treasures during World War II.

An alien landscape on the banks of the Aegean Sea.

A quirky bookstore hidden beneath a sea of whitewashed Greek villas.

Perched on a spindly rock spire in a Greek archipelago, this lighthouse would make a perfect wizard's tower.

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

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

One of Ireland's most infamous prisons for rebels including men, women and children.

This demon atop the Notre-Dame de Paris looks utterly bored.

A Belle Epoque bordello turned into a themed love hotel.

Dolls of all shapes and sizes display the eras of femininity in this spooky and beautiful collection.

Inside a former cabaret, seven floors of erotic art.

Claude Monet was baptized in this lavishly ornate Paris church.

This recessed garden protects thousands of mountain plants by creating its own microclimates.

Stripes of human ashes cover a back lawn in the most sought-after burial grounds in Paris.

An immersive projection art installation uses sound, scale, and light to take visitors inside classic works of art.

Walk through spectacular aisles of hanging meat and wagon wheel–sized cheese at the world's largest wholesale food market.

Collection of antique taxidermy and natural specimens, near one of Paris's oldest flea markets.

The industrial architecture honors the laborers who brought the Exposition Universelle of 1900 to life.

A magical, macabre wax museum, beloved by locals, uses real artifacts to depict an assassination from the French Revolution.

An unusual number plate signifies the building's saucy past.

Architect Le Corbusier built his friend a cubist house to match his impressive collection of cubist art.

Beggars were miraculously "cured" of their fake ailments when they returned home to this 17th century Paris slum each night.