How wide was the secret hallway behind the bookcase in Anne Franks House?

Read and look ... and let us know what you decide.

http://www.annefrank.org/en/Subsites/Home/About-the-house/

http://www.annefrank.org/en/Subsites/Home/

http://www.google.com/search?q=floor+plan+anne+frank's+house&espv=210&es_sm=119&tbm=isch&tbo=u&source=univ&sa=X&ei=MQl0UpqsN8fZsASJ2YGYBA&ved=0CDwQsAQ&biw=1440&bih=711