Secret passages, also commonly referred to as hidden passages or secret tunnels, are hidden routes used for stealthy travel, escape, or movement of people and goods. They are sometimes inside buildings leading to secret rooms.
View inside the Passetto, the secret passage between Vatican City and Castel Sant'Angelo in Rome, Italy
A secret passage in Bran Castle, a 14th-century fortress in Romania.
A trapdoor on the jungle floor leads down into the Củ Chi tunnels. Closed and camouflaged, it is virtually undetectable.
The camouflaged trap door, now open.
A sliding bookcase is a wooden shelf or cabinet for bound volumes that is designed to move on rollers, a track, hinges, or another mechanism and is typically used to hide the presence of a secret room or space. Sliding bookcases were used in the United States during prohibition to hide rooms or spaces containing liquor. They have also been used to conceal entrances to speakeasy bars and marijuana-growing operations. People have hidden in secret rooms concealed by sliding bookcases to escape detection from a government or police force.
The (reconstructed) movable, sliding bookcase that covered the entrance to the Secret Annex at the Anne Frank House