An ancient and majestic fortress that played an integral role in Portugal's road to independence.

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

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

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

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Fourteen sculptures showing the development of a fetus stand outside a hospital for women and children.

The enormous diamond-shaped building packs a trove of academic and literary treasures into one futuristic space.

This seemingly random 30-foot statue of an oryx in Qatar's capital was a mascot for the 2006 Asian Games.

Qatar's oldest market can trace its origins back more than a century.

This fountain pays homage to Qatar's history of pearling, the primary industry before oil.

The building is a gigantic piece of art inspired by the shape of a desert rose.

This 23-foot-tall bear stands amid the hustle and bustle of Hamad International Airport.

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

Dedicated to the American general whose reply to a German demand for surrender was simply "Nuts!"

This sprawling Belgian fort was once thought of as impenetrable but now it is simply an abandoned relic.

Housing the groundbreaking maps and globes of Gerard Mercator.

Six turbines towering over a wide road for passersby.

The compass on its front was a handy tool for 17th-century merchants who needed to know the direction of the wind.

Christ's blood preserved in a Belgian town.

Potato-peeling mannequins, Inca art, and a dangling tuber mobile help trace the history of fries at this Belgian museum.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

Each time a baby is born in Ghent, these streetlights flash in silent celebration.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

This memorial museum chronicles the apocalyptic destruction of the First World War.