Oh my goodness! That's funny...sort of... But I can relate to that. One of my very favorite venues here is out in the rain forest, by a beautiful river. Absolute perfection of dense woods and lees for camping, archery, etc. But...the soil is nearly solid with granite stones. Trying to sink an 18" iron stake for one's pavilion is almost impossible. I have damaged many a spike, and many, many portable holes in that ground. I empathize with your lack of soil! But krikey...4 inches? How do you do it??