These Things Are All Over The Place

Construction in my home town has uncovered a 12' X 30' cistern that lurked below the surface in a very public area. I run across old wells all the time out in the woods; that is why I keep a whistle on my compass lanyard. The story does not say what was over the top of this hole, but you have to wonder why it hasn't caved in and swallowed some unlucky individual in the last one hundred years.