Underground farmer's market, May 16th, somewhere in Amsterdam

Event: Underground Boerenmarkt @ near Downtown 75, Rokin 75 - follow the clues via Twitter, Sunday May 16th, 12.00 - 17.00, FREE. 

A wild underground farmer's market where a semingly "spontaneous" market arises somewhere in Amsterdam on Sunday.  Except an eating extravaganze with sweets, handmade kroketten, traditional mosterds, bier, jams, worstjes, soepjes, home grown sambal, gourmet food, and organic butchers.