A kaleidoscopic warehouse-maze of handmade neon signs.

The curios of pharmacist and collector Henry Wellcome.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

Double spiral staircases are not unheard of, but they are very rare.

Bizarrely-painted church designed by a controversial artist.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

A beautiful but toxic fountain of mercury.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

A temple to modernity, tucked away amid Barcelona's more well known museums.

This cafe offers a curated collection of treats and tipples made by monks and nuns.

Macabre museum devoted to historical Viennese murders.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

An eerie, derelict amusement park in Berlin.

Since ancient times these picturesque springs have been providing bathers with healing waters.

This 17th-century manor house provides a fascinating glimpse into old-world Mallorcan life.

This historical manor is complete with a magnificent garden.

Be(w)ar(e) the moat around this historic Czech castle.

Heralded as one of the prettiest castles in all of Czechia.

A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

A museum devoted to bringing to light forgotten or neglected histories through exhibitions, education and public programming.

The humble fort that saved Washington.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

Check out the underground party scene at the "Burning Man of Brooklyn."