Corn field is only 100 years old, nothing really old there. Hasn't been planted in two years and now is covered with weeds 10 - 24" tall. Can't get coil close to the ground but did manage to get three coins that were only 4 - 5" deep. Place is loaded with crushed soda cans 6" deep, they all sound like silver. Searched 4 hours in 95 degree heat but I had a good time anyway.