England's steepest street has such a drastic incline that locals tie their parked cars to lampposts when it gets icy.

A monument dedicated to the unrecognized Black "mother" of modern medicine.

This pedestrian walkway cuts through a cemetery and over several burial vaults.

This striking observation tower shaped like a spinnaker sail is the newest icon in historic Portsmouth.

England's most notorious suicide spot.

A hands-off space for graffiti artists to hone and display their skills.

An underground city of salt.

This arch granting triumphal entrance into Antalya was designed to honor the emperor's visit.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This demon atop the Notre-Dame de Paris looks utterly bored.

This unique building in the main square stands out among the city's typically Baroque architecture.

The floor of this spectacular Baroque sanctuary is covered in memento mori.

This church is named for one of the most dramatic tales in the early Christian church.

Dynastic Home of the De Piro Family.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

A graceful natural rock formation stands astride the point where the Gulf of California meets the Pacific Ocean.

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

Preserving the research tools, unexpected inventions, and odd collections of generations of college professors.

Fantastic views and thousands of love locks.

A museum and gardens with unusual plants and a history of progressive programming for the blind.

This magenta statue commemorates the legendary marriage between a mermaid and the city's founder.

Statues of a fire-breather, a clown, and a whole performing troupe celebrate Luxembourg's creative side.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.