There is something alluring about hidden spaces. I am not sure if it is the mystery, sense of adventure, possible mischief or merely the idea of sneaking away somewhere-known only to a select few. For some, this adventure begins and/or ends with a book. Buzzfeed (April 2013) posted 31 Beautiful Hidden Rooms and Secret Passages, using books as the main attraction/distraction.
Just for Fun: This week take a peek between (or behind) the stacks-to find something unexpected.