In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

This historic electric train has operated with regularity since the early 1900s.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

A surrealist timepiece by the artist of melting clocks.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

Vienna's underworld of tunnels and subterranean rivers made an iconic appearance in a 1949 Orson Welles film.

Inside the corridors of this flea market, visitors are sure to find some obscure and odd treasures.

A non-stop elevator ride in Vienna's city hall.

Along the edge of this fountain are 365 smaller fountains that represent the days of the year.

An ornate private entrance to the Vienna subway built specifically for the emperor.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Handsomely crafted representations of our round planet.

A spherical "micro-nation" in the heart of Vienna.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

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

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The beautiful baroque library of the Hapsburg empire.

A slice of central Asia in the middle of Berlin.

Part bookstore, part café, and part forest.

A 19th-century Baja cantina that many say is the birthplace of the margarita.

An underwater restaurant, surrounded by a coral reef.

Fine dining 20 feet below the surface in the Indian Ocean.