This trail was once used to smuggle cigarettes, sugar, and other black market goods between Italy and Switzerland.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

Lucerne's central prison was converted into a tourist hotel with a bare minimum of changes.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

This fountain is dedicated to the workers who perished constructing the Fréjus Rail Tunnel.

Beautifully decorated tarot cards from the Middle Ages.

A portrayal of two lamps embraced and in love.

A small island in Lake Garda that was used as a burial site, pirate hideout, and a monastery.

A unique form of erosion created an uncanny landscape of boulders perched atop slender columns of clay.

This small Milan street is filled with colorful homes and a rich history.

Acrosticism and palindromes on this randomly placed stone.

An exclusive waiting room built for the royal family in the 1920s is hidden in Milan’s central station.

The train platform where Jews were sent to concentration camps is now preserved as a Holocaust memorial.

An underground passage is home to a guillotine that predates the French Revolution by more than two centuries.

This sculpture of a rhinoceros suspended above a city square is meant to evoke the weight of the human condition.

An unusual round church in London with a Templar past.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

The works of poetry's biggest names grace the walls of the city of Leiden, all carefully painted by hand.

Old ships and machinery fill a historic harbor in the city that's home to Europe's largest port.

Stained-glass windows inspired by Vincent van Gogh's paintings decorate this church in the town where the artist's career began.

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

The house where Harlequin was born.