19th Century Ward Lock Key

19th century iron ward lock key...4.5"...UK/Ireland...as-found condition, a bit of rust but solid.

A warded lock/ward lock uses a set of obstructions, or wards, to prevent the lock from opening unless the correct key is inserted. The correct key has notches or slots corresponding to the obstructions in the lock, allowing it to rotate freely inside the lock.The warded lock is one of the oldest lock designs which can be found as far back as ancient China and Rome.During the Middle Ages they were used prolifically on monasteries where, because money and time were not issues, their complexity grew. Warded locks are still in use today in the UK and Ireland for low security applications, and on heritage sites such as ancient monuments and churches to preserve original features.