The oldest known lock was found by archeologists in the Khorsabad palace ruins in northern Iraq.
It was estimated to be 4,000 years old --
the same era as the Bronze Age and the invention of writing.
Locks and latches are key parts of the gates and doors, fences and walls that
offer privacy, protection and safety for the "insiders" and
leave the "outsiders" excluded, rejected and curious about what's behind that barrier.
After 40 centuries of adaptation, the variety of locks and latches is astounding.