Clever Lock from 1680

This "detector lock" in the Rijksmuseum was created by British locksmith John Wilkes.

"The keyhole for this lock is concealed behind the man’s left leg. The lock opens and closes when the key is turned twice. With two complete turns of the key, the dial at which the man’s stick is pointing rotates. This records how often the lock has been opened. The doorknob is released when the man’s hat is pushed aside."

Via