Thousands of colorful pirogues showcase ingenious craftsmanship at the largest fishermen port in Nouakchott.

This remarkably well-preserved mosque stands amid an 11th-century caravansary.

Five ancient libraries, little changed for centuries, preserve a medieval archive of Quranic lore and civic documents

A geological bull's-eye visible from outer space.

Climb atop one of the world's longest and heaviest trains for an unbelievable journey across the Sahara Desert.

A brutalist gem towering over the heart of Milan.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

This giant middle finger statue sends an unambiguous message to Italy's bankers.

A beautiful discovery site of prehistoric burials.

Washington's iconic carousel has a nice piece of Civil Rights history.

An abandoned bell tower in the middle of nowhere is the last testimony of a forgotten medieval village.

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

This tiny train shuttles passengers to one of Northern Ireland's most spectacular sights.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

Northern Ireland's Brobdingnagian stepping stones.

This massive monument has been telling the time for 150 years—at a slight angle.

Belfast's namesake river still winds below the city center, hidden from sight.

A palatial former bank building now houses what may be the poshest art venue (and former Tesco) in Belfast.

Dublin's most modern, visually spectacular bridge is modeled after Ireland's national emblem.

The modern birthplace of Irish freedom.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

The castle still holds traces of the abandoned Roman fort it was built atop.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.