Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

Founded in 670, this ancient mosque is an architectural time portal.

A painting in the historic Cathedral Basilica depicts Jesus and his disciples dining on a traditional Peruvian menu.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

This subterranean funicular is one of the world's smallest subways.

A small museum houses a long, rich history of life and death on Lake Erie — from famous shipwrecks to rum smugglers.

The glowing blue Nymphaeum of Emperor Tiberius.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Geothermal waterfalls in Tuscany.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

The largest stone moai on Rapa Nui.

The 953 windows undoubtedly make this the world's most beautiful screened porch.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Popular tourist destination where witches in dark hats sell dried llama fetuses for good luck.

A book collector's dream, this Toronto bookstore has the world's first "Biblio-Mat," a random book vending machine.

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

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

Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

Famously misunderstood wonder of the ancient world

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

Try not to get slimed in Tribeca.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.