Arrowheads are an item that players can find by cleaning an uncleaned find as part of the Varrock Museum activity. Unlike arrowtips, players cannot add them to headless arrows to make arrows. The arrowheads have no use, but you can put them in the crate by the southern-most door for a small reward, like a pot, or a bowl.
Often, players new to the Varrock museum misinterpret the arrowheads to be arrowtips, which members may use in Fletching. However, when they try to connect the arrowheads with headless arrows, nothing interesting happens.