That's what my first thought was, but there isn't any writing on it and the closest cemetery is like 20 miles awayLooks like a tombstone to me.
Need more info.... barnegat bay where? What is it's composition? Copper, Steel, cast iron, Bronze? Does a magnet stick to it? Heavy? Looks like a church steeple cross. Any markings?
Looks more like decorative stone work from an old church. I highly doubt the tombstone theory. Was there anything around it that could have been building rubble?
