Sawmills are buildings that process logs and trees into usable lumber. They may feature extensive conveyor systems that guide the wood to large circular saws which slice through it. In game or narrative worlds these elements may be areas characters can explore or dangerous terrain hazards. In game worlds with a resource economy, sawmills may be a source of lumber. Sawmills are often located on the outskirts of a forest town and may be located on a river – both because the sawmill may also be a watermill and logs are often transported by river to the mill from an upstream logging camp.