St. Leonard's Tower in southern England is a mysterious place—historians aren't sure exactly who built the Norman tower keep more than 900 years ago, or why. And now, they're not sure who "borrowed" a key to the tower and returned it 47 years later, the Guardian reports. The English Heritage charity, which runs the site in West Malling, Kent, says the large brass key was received in the mail along with an anonymous note. "Borrowed 1973. Returned 2020," it said. "Sorry for the delay. Regards." The key is believed to be around 100 years old. English Heritage says it doesn't know how the key went missing.
Roy Porter, English Heritage’s senior properties curator, says they would like to reward the individual who returned it. "It’s certainly one of the most puzzling packages we’ve ever received and just in time for Christmas. It’s a modern mystery to add to the historical questions posed by the tower," Porter tells KentOnline."We’d love to reward the honesty of whoever returned the key with a gift of membership. If that’s you, please get in touch.” The charity says the tower is an "early and well-preserved example of a small free-standing Norman tower keep," though it's not clear whether it was once part of a larger castle. (After 15 years of bad luck, a Canadian woman returned artifacts she had taken from Pompeii.)