Keys to the Doors

But which doors?  The key above is around 500 years old and the one below some 250 years older than that. Each is about 12cm long.   I wonder where they've been, what history they've seen in their life so far and whose hands they've passed through?  Neither would appear to have been buried in the ground as they're not corroded enough.  At least they are keeping up with the times and have made it to cyberspace!