Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

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

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

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

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

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.

A strange egg in a mucky bog of western Ireland marks the spot of an aviation milestone.

A stunning medieval castle owned and restored by the famed actor Jeremy Irons.

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

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

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

A history of heat is on display at this unique Austrian museum.

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

Museum devoted to the artificial language of Esperanto.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

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

Handsomely crafted representations of our round planet.

The topiary maze at the Habsburg hunting lodge.

The scars of World War II are preserved on its walls.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

This airport currywurst stand is made out of retro airplane parts.

Revitalization efforts converted a former U.S. military heliport into a sprawling urban park.

This museum explores the history of the city's public transportation. Its collection includes the world's oldest preserved electric trolley car.