Sometimes hidden passages are created out of necessity for a functional space. Userjb2411 on ContractorTalk.com was hired to build a backyard deck. The deck was going to be at door level and cover over the exterior doors the basement cellar. To retain access to the cellar and have a functional space, two trap doors were built into the deck.
There is a visible handle built into the floor here. It could be covered with a rug, or you could incorporate a concealed handle if you wanted to completely hide an access point like this.