A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

In an area known in Bratislava’s postal history, this sculpture sits equipped with a functional postbox.

This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

Original cabaret handbills, posters, and feline artwork are a purrfect highlight of the Museum of Montmartre.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

Museum covers every step of the chocolate-making process, from cultivation to the finished product.

Ancient man-made caves underneath small town Belgium.

A reconstructed World War I-era communications array that was once hidden in plain sight.

Dedicated to the American general whose reply to a German demand for surrender was simply "Nuts!"

A giant bug impaled on a 75-foot-tall needle.

This old, abandoned hotel offers magnificent views.

Explore 400,000 years of humans' "battle against darkness" in this offbeat but thorough lamp museum.

Only museum in the world devoted to bookbinding and book arts holds a permanent collection representing five centuries.

Somewhere there is a giant who can no longer poop, but now travelers can stay inside his anus.

This Greek temple, open only an hour a day, was the site of a war of tastes between an architect and an artist.

This recently restored crypt was once plagued by liquefying coffins and exploding caskets.

Personal garden filled with mosaics made of recycled garbage.

Walk through living pictures and music in the Cathedral of Images.

From carts to cars, this leftover Roman bridge in France has managed to survive for centuries.

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

A unique underground structure dating back to the 1st century BC.

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.