Temple locks or Laconian locks

Temple locks, or Laconian locks, consisted of a wooden bolt on guides on the inside of the door. Through a hole in the door, a person on the outside could slide the bolt back to open position using a very angular tool (key) of bronze or iron. To lock it again, a thin rope or leather strap pulled the bolt into the staples in the door frame. Ancient Greek door locks were used from the seventh century BC in Greece and were named after finds in Laconia in the southern part of Peloponnesus in Greece.

A temple servant carries a key on her shoulder.  From Technik des Altertums

Laconian lock, mounted on staples on the inside of the door. The lock opened from the outside. The rope pulls the bolt back to closed position. From Technik des Altertums. Sketches by the author.

Temple servants with keys on their shoulders. Sketches by the author.