I recently got a mechanical ladies Bulova from a yard sale. After opening it up to get a look at the movement, I was impressed by the how tiny it looked. It measures about 18mm X 16mm.
So my question is, what is the smallest mechanical movement ever produced? I realize that this is probably a hard question to answer considering that small watch movements tend to come in non-circular shapes, but in terms of approximate overall area, what is the smallest.