Hidden is related to Surprise. Surprise is related to Obvious. 
you are likely to find Garage in/at/on Downtown. you are likely to find Ladder in/at/on Garage. Ladder is a type of Tool. Tool is related to Useful. 
Hidden <--RelatedTo--> Surprise <--RelatedTo--> Obvious 
Downtown <--AtLocation-- Garage <--AtLocation-- Ladder --IsA--> Tool <--RelatedTo--> Useful 