Mill can be used for Flour. you are likely to find Mill in/at/on Town. you are likely to find Town in/at/on County. 
Pit is related to Valley. you are likely to find Valley in/at/on Continent. 
Flour <--UsedFor-- Mill --AtLocation--> Town --AtLocation--> County 
Pit <--RelatedTo--> Valley --AtLocation--> Continent 