In August 1942, Johan Voskuijl built a hinged bookcase to conceal the entrance to the Secret Annex.
‘Our hiding place has now become a true hiding place. Mr. Kugler, you see, thought it would be better to place a cupboard in front of our door, (there are a lot of searches being carried out for hidden bicycles,) but then of course a cupboard on hinges that can open like a door. Mr. Voskuijl built the piece of furniture.’
Anne Frank, 21 August 1942
At the back of the bookcase, a wooden bobbin hung on a piece of rope attached to a hook. It was used to open the entrance.
The original bookcase is still part of the museum today. The bobbin is fragile and therefore kept in the depot.