That's what we just found this evening in our yard by the driveway into church.
Peter was walking by the drive way and stepped on some top soil left over from a flower barrel. It gave way. Mercifully, Peter just stepped over it and away from it. It opened a hole just larger than the size of his foot.
We looked and noticed that the hole went down, mainly under the asphalt driveway, quite a ways. Caleb put in a broom and did not find the bottom. Philip stuck down a hockey stick as far as he could reach. Still no bottom. I put a 25 foot tape measure down. Still did not hit the bottom.
After contacting some church council members, I was advised to call 9-1-1. The Novi Police came (3 squad cars -- a slow night combined with curiosity?) and shone a better flashlight than I had into the hole. The conclusion: It was a well, about 30 feet deep.
Whatever had been put on top of it to cap it must have deteriorated and gave way. Once again, we are grateful that we did not discover this in a much more tragic fashion. Hopefully, it will be filled in without much delay and without too much cost.