A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

France's most famous cemetery, with some of its most curious tombs.

Soaring over the Niagara Whirlpool since 1916.

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

Every equinox this Maya pyramid puts on a spooky ancient light show.

This staircase in a lush tropical grotto was built by enslaved laborers and renamed to honor Queen Victoria's role in ending slavery in the British Empire.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

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

Ugly 18th-century dwarf statues living in a perfectly landscaped Austrian garden.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

The Habsburgs' royal collections of art and wonders.

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

Largest illuminated advertisement sign in the world.

Fantastic views and thousands of love locks.

This futuristic German television spire is actually the world's largest digital clock.

This historic funicular system combines the old with the new while offering delightful views over the surrounding valley.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

Twisted buildings adorn the banks of the Rhine river.

The last bastion of Roman presence north of the Alps looms over a German town.