Joshua 8:28-31

So Joshua burnt Ai, and made it a heap for ever, even a desolation, unto this day. And the king of Ai he hanged on a tree until the eventide: and at the going down of the sun Joshua commanded, and they took his body down from the tree, and cast it at the entrance of the gate of the city, and raised thereon a great heap of stones, unto this day. Then Joshua built an altar unto Jehovah, the God of Israel, in mount Ebal, as Moses the servant of Jehovah commanded the children of Israel, as it is written in the book of the law of Moses, an altar of unhewn stones, upon which no man had lifted up any iron: and they offered thereon burnt-offerings unto Jehovah, and sacrificed peace-offerings.