The great appeal of Maurice Sendak's 1964 Caldecott Medal-winning children's classic Where the Wild Things Are is that it dared to go to the dark side. Its pages are filled with fanged monsters, oafish ogres, and nightmarish settings rarely explored in kid lit, much to the delight of legions of monster-loving children. If you and your family would like to learn more about the mysterious, creative genius that is Maurice Sendak—now 81 years old—start planning a trip to Philly.

You can catch “There’s a Mystery in There: Sendak on Sendak” at Philadelphia’s Rosenbach Museum & Library through May 3, 2009. This major retrospective includes over 130 pieces pulled from the museum’s vast Sendak collection, plus over 300 original watercolors, rare pen-and-ink sketches, doodles, manuscripts, books, and dummy books from the 1950s (lest you forget that Sendak also illustrated Else Holmelund Minarik's Little Bear series) to today.  You can also watch interviews with Sendak through digital touchscreens throughout the galleries. Kids will love the artwork from Sendak’s books, while grown-ups can learn more about his personality as a storyteller and the mysterious undercurrents that weave their way through his work.

Can't make it to Philadelphia? Good things come to those who wait. The exhibition will begin a national tour in the summer of 2009.