An outsider art duo's yard has been turned into a whimsical public gallery.

Nine caves filled with recently-discovered archaeological finds under the houses and the streets of the most ancient district of an old town.

This picturesque Umbrian city has a subterranean side that has long remained hidden.

Water and windows define this defensive Italian well.

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

Elaborate tile work in this railway station tells the story of Portugal.

A hidden three-foot-wide house separates these two regal churches.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

Eat the ultimate iteration of Portugal's most beloved pastry.

Located in the thermoelectric factory that once powered the entire city, this Portuguese museum is shockingly fascinating.

The devil-defying mark left by a saint as a boy is visible inside Lisbon's cathedral.

The world's oldest bookshop still in operation.

The best place in the world to buy tinned fish.

Hidden beneath a beautiful overlook you’ll find the history of the city depicted in comic strip format next to a pay toilet.

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

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

One of the smallest bookstores on the planet.

Catering to broken dolls for almost 200 years, this repair shop is now a charnel house of doll parts.

Sip cherry liqueur at a bar dating back to 1840.

The scorched Lisbon church that survived two earthquakes and a massive fire.

On the wall of this medieval walkway, a symbol of the Spanish Inquisition.

An abandoned Nazi explosives plant founded by the inventor of dynamite is now an underground museum.