Atlas Obscura is hosting the second annual International Obscura Day on April 9, 2011, in partnership with Hendrick’s Gin. This is a day set aside for “expeditions, back-room tours and hidden treasures” in places near or not-so-near. Events will take place in 61 cities (so far). Here are some of the most popular:

In London Go out for adventure films and cocktails in the historic Royal Geographical Society Map Room

In San Francisco The National Parks Service is leading an exclusive, behind-the-scenes tour of Alcatraz followed by drinks at a speakeasy

In Los Angeles Wander the Magic Castle and mingle with Magicians while sipping Cocktails

In Brooklyn Marvel at a recreation of Coney circa 1910, see the worlds best sideshow performers, and meet the stars of Discovery’s Oddities

In Florence Explore the macabre and beautiful La Specola anatomical museum

In Paris Join an expedition into the abandoned ruins of a Victorian-era tropical botanical garden

In Rome Go underground to explore ancient catacombs

In New Zealand Tour the museum of extraordinary visual design company WETA best known for their work on the Lord of the Rings Trilogy

In Antartica Join in a celebration of the hundred year anniversary of the heroic (and tragic) Amundsen and Scott race to the South Pole.

If none of these events are near you, there are plenty more to find at Atlas Obscura.