secret passage

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. Others allow people to enter or exit buildings without being seen. Hidden passages and secret rooms have been built in castles and houses owned by heads of state, the wealthy, criminals, and abolitionists associated with the American Underground Railroad. They have helped besieged rulers escape attackers, including Pope Alexander VI in 1494, Pope Clement VII in 1527 and Marie Antoinette in 1789. Passages and tunnels have been used by criminals, armies (notably the Viet Cong in the Vietnam War) and political organizations to smuggle goods and people or conceal their activities. Appearance and construction Entrances to some secret passages appear as architectural features, such as a fireplaces or built-in sliding bookcases. Some entrances are more elaborately concealed and can be opened only by engaging a hidden mechanism or locking device. Others are much simpler; for example, a trapdoor hidden under a rug. Some buildings have secret areas built into their original plans, such as secret passages in medieval castles, designed to allow inhabitants to escape from enemy sieges. Other castles' secret passages led to an underground water source, providing water during prolonged sieges.