For all of humankind’s history, we’ve been fascinated with hidden places. Before they were a fun architectural addition to new homes, hidden rooms and secret passages served a purpose. Most often, that purpose was to allow someone to hide or escape from some kind of danger. At other times, though, they have served a much more sinister purpose.
Hidden passages have a long history of appearing in fictional novels and films but an even richer past in reality dating back to Egyptian tombs passages for Christians to worship in hiding from Romans. full story via weburbanist
King Charles II's several homes with hidden chambers during the English Civil War
H.H. Holmes's (born Herman Webster Mudgett) enormous building in Chicago, late 1800s
During America’s Prohibition period of the early 20th century, the alcohol trade (and the associated gambling and prostitution trades) underground place.
The hidden rooms of the Holocaust era by ten Boom family of Haarlem, the Netherlands