An arcade packed with a rotating collection of unique independent video games.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

Try not to get slimed in Tribeca.

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

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

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

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

The house that took a plunge into the facade of a museum.

Journey through a mesmerizing array of board games inside this museum.

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

A magnificent collection of imperial armor and weaponry.

This grand manse has been transformed into a museum devoted to one of the founders of Fantastic Realism.

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

Legends surround an ancient tree trunk riddled with nails for good luck.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

The resting place for anonymous victims of the Danube's dark waters.

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

Op-art architecture designed for happiness.

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

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

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

The topiary maze at the Habsburg hunting lodge.