Strange Abandoned Property

This is a strange abandoned property that I can't determine the purpose of. Their is a small dirt road that enters it and is blocked by a chain with a DANGER sign (see pics). The property is covered in strange rising lumps of soil that do not appear to be natural - there may be something underneath them. It looks as if it was once a field that has been slowly overgrown. There are random dirt grooves all over the property. It is relatively large and the value of the area is moderately high, making it pretty unusual. While there I was walking around and found a completely hidden little shed that was half destroyed with a well near it and evidence of a building perhaps once being there. If anyone has any information about the purpose of this plot of land it would be greatly appreciated!