Joshua 8:28-31

So Joshua burned Ai and made it a heap forever, a desolation until this day. He hanged the king of Ai on a tree until evening; and at sunset Joshua gave command and they took his body down from the tree and threw it at the entrance of the city gate, and raised over it a great heap of stones that stands to this day. Then Joshua built an altar to the LORD, the God of Israel, in Mount Ebal, just as Moses the servant of the LORD had commanded the sons of Israel, as it is written in the book of the law of Moses, an altar of uncut stones on which no man had wielded an iron tool; and they offered burnt offerings on it to the LORD, and sacrificed peace offerings.