One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A botanically themed auditorium blooms within the world’s last operating double-decker theater.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

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

Famously misunderstood wonder of the ancient world

Original cabaret handbills, posters, and feline artwork are a purrfect highlight of the Museum of Montmartre.

One of the longest wooden benches in the world snakes around Geneva's Treille Promenade.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

The world's most active stratovolcano is almost always erupting.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

A medieval fountain lined with 99 unique stone faces whose origins and meaning remain unknown.

Ever loyal to Roma, the small village of Albe in the Abruzzo region carried on until an earthquake did it in.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Pilgrimage site for star-crossed lovers.

A military museum, art park, mausoleum, and architectural oddity all on one fascist's estate.

A sculpture serving as an homage to Pope John Paul II.

The studio built by fascists in the hopes of "reviving the film industry" with the occasional propaganda film opportunity thrown in.

If you want to talk to the Pope you will have to stare down this surreal vision of Jesus rising from a nuclear hell.

2300-year-old Roman road connecting the empire.

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