The centuries-old trees lining both sides of this dirt road may become Madagascar's first natural monument.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

These ancient sunken lanes were naturally tunneled into the soft ground by countless footsteps.

A once-thriving hotel in the Swiss Alps couldn't compete with climate change.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

An amazing collection of wax anatomical models and terratological models.

This subterranean studio is filled with fascinating kinetic art.

An overgrown and largely forgotten cemetery lies hidden within the outskirts of Amsterdam.

A Portuguese Jewish cemetery filled with stunning grave monuments that date back to 1614.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

A curious collection dedicated to human and animal anatomy and pathology.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

A space dedicated to contemporary art and culture, co-chaired by fashion icon Miuccia Prada.

This poignant art installation raises awareness of violence against women.

Nestled in the heart of Milan is a real wunderkammer of morbid curiosities.

The odd depiction of the Virgin Mary and baby Jesus is rooted in the Catholic Church's eradication of Catharism.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

Every inch of this chapel is covered in craftsmanship from across the world.

The world's most active stratovolcano is almost always erupting.

Haunting graffiti left by prisoners of the Spanish Inquisition.