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

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

One of Canada's most incredible rare book collections holds hundreds of thousands of gorgeous tomes that the general public can touch.

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

Lost subway station nestled beneath Toronto's busy commuter line.

A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

Japan's largest collection of Western-style mansions in the port city of Kobe includes a recreation of Sherlock Holmes' 221B Baker Street quarters.

A restaurant modeled after feudal Japan, where the waitstaff are trained as ninjas.

One of the first hotel rooms in a pod.

A taste of the macabre Tokyo's ritzy shopping district.

The iconic Manhattan corner that was once the site of the Beastie Boys' fake clothing store.

The "Seinfeld" diner.

Great place to have a drink and a bite to eat in an atmosphere laden with New York's Bohemian past.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

From lefty Jewish gathering site to hip cultural site in just 80 years.

The skyline of Montreal includes the silhouette of an unexpected fruit-shaped Canadian staple.

One of Canada's oldest museums, the beautiful Redpath has been serving up Natural History and Ethnography since 1882.

This 1967 experiment in modular architecture was designed to be a new model for urban living.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

On a winding Vienna side street, one museum has turned their windows into a monument to history’s peace-minded heroes.

Located right outside of Vienna, visitors can take in expansive views of an ethereal forest.