This sliding secret bookcase door conceals a laundry room. It uses skateboard wheels, and could be used to hide any number of different entrances.
Ikea bookcase used as a hidden sliding bookshelf door
Secret sliding bookcase door conceals hidden Murphy bed
The video is tilted sideways, but this secret bookcase door slides straight back into a small room. They use some type of hanger/slides at the top of the bookcase. This gives me some ideas.
Sliding door bookcase - several deep
Sliding bookcase door conceal hidden passage from http://www.hiddenpassageway.com
