Joshua 8:28-31

So Joshua burned Ai and made it a heap forever, a desolation to this day. And the king of Ai he hanged on a tree until evening. And as soon as the sun was down, Joshua commanded that they should take his corpse down from the tree, cast it at the entrance of the gate of the city, and raise over it a great heap of stones that remains to this day. Now Joshua built an altar to the LORD God of Israel in Mount Ebal, as Moses the servant of the LORD had commanded the children of Israel, as it is written in the Book of the Law of Moses: “an altar of whole stones over which no man has wielded an iron tool.” And they offered on it burnt offerings to the LORD, and sacrificed peace offerings.