An underground city of salt.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

These rock drawings in the Côa Valley also create an ancient optical illusion.

When Azorean green tea meets volcanic hot springs water, a luminous brew is born.

This unique architectural wonder is also tied to one of the 20th-century's most renowned writers.

One artist's collection of homemade handicrafts doubles as a monument to 20th-century material culture.

An abandoned anti-smuggling station decays along the boundary between Portugal and Spain.

In the Monastery of São Vicente resides a gallery devoted to a breathtaking collection of seashells.

This Portuguese bullring is built right into the caldera of an island volcano.

This impressive rupestrian engraving dates back to the Upper Palaeolithic period.

These small, triangular, colorful houses are a staple of Madeira Island.

Come for the bread-themed puppet show, stay for the buffet.

Tucked away inside this concrete building is a church and its grand display of brutalist architecture.

This oddly shaped church resembles a rocket.

Europe's oldest still-operational tea farm also boasts a spectacular view.

This architectural beauty is the home to a personal collection of more than 600 examples of mechanical musical instruments.

A small but charming botanical garden that contains many exotic plant species.

One of the few places in Portugal where the Celtic ritual of wearing large wooden masks is still practiced.

One man's remarkable private collection of art from around the world.

Europe's largest collection of matchbox designs is a fascinating exploration of the cultural history of the world.

An ancient tomb that still stands in Portugal.

An abandoned tuberculosis hospital said to be haunted by the patients who died within its walls.

A neolithic tomb converted into a tiny chapel.