Why a column on the entrance is inscribed with a verse from the Quran is one of Sicily's many mysteries.

Bali's remote "gateway to heaven" is one of the most sacred places on the island.

A Japanese cat island also populated by the descendants of a band of banished samurai.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

Go inside to really appreciate this 500-year-old technological masterpiece.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

A whimsical bridge adorned with decorative dragons.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

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

The Sighignola summit on the Swiss border offers views so breathtaking it's been named one of the most beautiful places in Italy.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

Woven tree art gives this towering Australian woodland a touch of mystical whimsy.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This small group of sand dunes manages to pack in a strange rainbow of colors.

The steepest classic funicular in the world glides along a dizzying incline.

This unimaginably large pile of sand near Nazca is one of the tallest dunes in the world.

A city block packed with whimsical sculptures that seem to be plucked from a tiled fantasy world.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

Iceland's only steampunk shop imagines a retro-futuristic world that never was.

A constellation of golden cobblestones shows the names of local children born under a full moon.