A beautiful but toxic fountain of mercury.

This glass skywalk offers vertiginous views down the volcanic cliffs to the beach below.

The ancient sauropod tracks found in this former quarry are some of the largest in the world.

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

An ancient tomb that still stands in Portugal.

Entire apothecaries are on display at this Lisbon museum, which explores the history of medicine.

This museum contains a vast array of puppets and marionettes from all over the world, featuring incredible works by Portuguese creators.

Rainwater transformed this old quarry into a peaceful pond you won't find in most tourist books.

One of the world’s longest pedestrian suspension bridges.

Portugal’s highest lighthouse has one of the most impressive focal planes in the world.

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

This giant sculpture made of trash is a critique of society's wastefulness.

Men in rubber-soled boots serve as your "brakes" on this toboggan ride Hemingway described as "exhilarating."

A windswept necropolis carved into the rocks overlooks the "most Portuguese town in Portugal."

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

A lush oasis full of vibrant plants and striking geometric displays.

Building owners can take out tiles for free at this repository for historic building materials.

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

This crumbling Portuguese ruin overlooks the populace it once ruled.

One of the largest Roman settlements in Portugal.

A perfectly circular lake is formed by the crater of an ancient underwater volcano.

A 19th-century mansion houses the largest collection of gin in the European Union.

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.

Local lore says the devil built this beautiful medieval bridge to help a fleeing bandit.