San Gennaro, the patron saint of Naples, greets pedestrians between these narrow city streets.

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the 20th century.

France's most famous cemetery, with some of its most curious tombs.

A dozen cast iron leopards stand guard along the length of Aberdeen's Union Bridge.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

This Greek temple, open only an hour a day, was the site of a war of tastes between an architect and an artist.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

This lucky bronze frog was gifted to Madrid by a casino.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

This unattributed sculpture in Amsterdam is hiding in plain sight.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

A strangely curved lamppost stands tall over this avenue in Rotterdam.

A giant yellow phallus sculpture hidden in the gardens of the Museum Boijmans Van Beuningen.

This monumental mural crafted nearly 40 years ago is still in perfect condition.

This statue honors the thousands of Allied avians that served and died for France during World War I.

Tables of secondhand books fill the inner courtyard of this 17th-century stock exchange.

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

This massive blockhead sculpture hides an entire library.

Museum celebrating the ocean, with the largest wunderkammer dedicated to sea exploration.

Massive galleon from a box-office bomb docked in Genoa.

This cathedral hides a sculpted dog that determines your fate and an unexploded shell from World War II.