This little-known national museum houses over 40,000 works of art from across the world.

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

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

Dead weights honor the dead of Portugal's fishing industry.

At night, bats patrol this magnificent 18th-century space in search of book-eating pests.

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

This abandoned five-star hotel is now a five-star urban exploration destination.

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

This now abandoned restaurant provides some of the most amazing views of Lisboa.

The medieval castle built as headquarters for the Pope's secretive Knights Templar.

Perhaps the most spectacular grotto along the Algarve coastline.

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

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

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

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

Houses are tucked between, on, and underneath giant boulders.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Throughout this shopping mall are medieval ruins that were discovered during the mall's construction.

A series of playful yellow penguins share a serious message about the environment.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

Countless grotesque faces stare out from this eerie Prague art wall.

Home to three historic ships from the age of Vikings.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

The old observatory in Copenhagen has a spiral corridor used as a racetrack.