In my area I have found 3, You need to look at old maps and then look for wooded areas that used to have homes on them. The 1874 maps for Lorain county Ohio show were all the structures were back then. Try this site Historic Map Works, Residential Genealogy ?
Most cellar holes for old farm homesteads are normally filled in and plowed over and are part of active farm fields. Farms used to be smaller since they horses were used to plow, You will find that newer farms are bigger since they have better equipment. I use 2 monitors when I search, one with the old map up and the other I have googles maps, satellite view up looking at the same area as the map.
Here are a couple of samples for the cellar holes I found on city property in Oberlin Ohio.
Old Map look at the L. E. Preslar and D.M Ward properties (lower left on the map
Satellite view of these properties
I actually had to go into the wooded area and found both cellar holes. Ones is full of trash, mainly broken glass and the other is full of water. I have found relics and older bottles, but no coins yet.