The Tower of London is a 900-year-old castle and fortress in central London that is notable for housing the crown jewels and for holding many famous and infamous prisoners.

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Throughout its history, the tower has served many purposes: it housed the royal mint (until the early 19th century), a menagerie (which left in 1835), a records office, an armory and barracks for troops. Until the 17th century, it was also used as a royal residence.