We went metal detecting in a building center at night we parked the car in a parking lot and went across the road into the building center we were going up and down so we could detect the whole square our first find was a piece of iron so we knew there was going to be a lot of iron there, on our second find we found more iron then we found coal that was very annoying bucause when we go metal detecting in the woods we find coal and when we go to the beach we find coal but in the woods mostly shotgun shells , but we knew now that we found a lot of coal and a lot of iron we knew there was going to be alot of it, about half an hour later we cept finding coal and more iron UNTILL WE FOUND SOMETHING THATS TOT COAL OR ITON , A BUTTON a medieval button wow we were finding a lot of buttons in the woods but it was just surprising when we found something that was not coal or iron we spen about a nother half and hour seaching in that big square hoping to find somthing good again but no, in the distance there was a big pile of mud witch we guessed its all the mud they took out to make the square so we metal dected up there for a bit but just found coal and little tiny bits of iron so we went home and but the button in some salt ,vinegar and baking powder cause that is suppose to help clean the button we couldn't really tell but we found one the same size as it and same shape and the one we found in the woods was a medieval one so we think its a medieval one