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

The celebrated eyesore created by starry-eyed sweethearts.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

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

The ancient tomb acts as a calendar that keeps perfect time.

Frida Kahlo's childhood home, now a museum of her life and works.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Some of the smallest works of art in existence.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

Happy harbor seals frolic and snooze on this warm, sandy stretch of coast.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

Plagued by riots, celebrity injuries and a tragic death, this amusement park has been demolished.

Try not to get lost in this picturesque Brazilian labyrinth of the dead.

The "Seinfeld" diner.

A kaleidoscopic warehouse-maze of handmade neon signs.

A mysterious shape catches the eye in this 16th-century painting.

Beautiful public park off the beaten path and away from tourists.

Crumbling remnant of Rio's colonial past tucked behind Corcovado mountain in the neighborhood of Cosme Velho.

A 125-meter long "tribute to the Brazilian people."