A monument to a working class martyr.

A Christian retreat founded to welcome refugees fleeing from the Nazis during World War II.

Medicinal spa created with the discharge from a geothermal energy plant.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

The incorrupt tongue of the patron saint of lost things is venerated in this basilica.

Thanks to both terrific preservation and historic vandalism this ancient site is known as the "Heart of Neolithic Orkney."

A bronze statue dating back as far as 1252, still has remnants of gold on its right cheek from ancient gilding.

After a profound show of devotion for his master, a dog becomes the symbol of loyalty for an entire nation.

The Buddhist temples of Yamadera, built into a mountain side, feature a viewing deck with sweeping views.

Even France's favorite aquatic son Jacques Cousteau, couldn't get to the bottom of it.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

England's oldest surviving hedge maze has been confusing visitors for over 300 years.

The granddaddy of English geoglyphs dates back to the late Bronze Age.

Giant naked man on a hillside.

The largest stone circle in the world has ended up bringing up more questions than it has answered.

The first archaeological site discovered by aerial photography.

Famously misunderstood wonder of the ancient world

Go inside to really appreciate this 500-year-old technological masterpiece.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Cold war icon and onetime "hole" in the iron curtain.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Italian cave with exceptional acoustics and an unsavory history.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.