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

Dine amidst exotic plants at this former royal greenhouse.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

This museum promotes informed contraception by documenting its often secret past.

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

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

Designed as a reminder of one of the darkest moments in Austrian history.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.

The block of aged dairy is probably still edible after 2,300 years in a peat bog.

Every year, the colorful murals of Montreal get a complete makeover.

This super steep hike ascends 2,000 feet in less than a mile.

While most of the games in this arcade take quarters, that would have been a small fortune when they were made.

There are eight natural springs around town, each with a slightly different taste.

A museum marks and documents the site of the Titanic's launch.

The last Victorian market in Belfast.

The only monument to name all of the passengers and crew who died on the RMS Titanic.

The ship built to ferry passengers and goods to the doomed Titanic is now the last remaining White Star Line vessel.

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

A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

Baroque celebration of the end of the Great Plague of Vienna.

Every weekend, people gather here for a brief chance to see their loved ones on the other side of the United States–Mexico border.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.