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

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

This former insane asylum now holds a pathological anatomy museum.

One New Hampshire alleyway has become home to a public gallery of feline art.

The largest arcade museum in the world chronicles the golden age of video games which ended promptly in 1987.

Ruins of the elaborate house where the enigmatic costume designer threw glamorous parties for New York's theatrical elite.

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

The history of radiation is on safe display at the foot of a radiation science laboratory.

An off-the-beaten-path boutique stuffed with an eclectic collection of upcycled goods.

A subterranean shelter remains intact under a busy Paris railway station.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.

Pitié-Salpêtrière was the dumping grounds for women who received the dreaded diagnosis of "hysterical."

A curious collection of locks and keys.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

A museum of carnival attractions where you are invited to ride the rides.

A museum of magic with a Sadist past.