District is related to Town. Downtown is derived from Town. you are likely to find Theater in/at/on Downtown. 
you are likely to find Clock in/at/on Airport. Face is part of Clock. Face is related to Part. Part is related to Heal. 
District <--RelatedTo--> Town <--DerivedFrom-- Downtown <--AtLocation-- Theater 
Airport <--AtLocation-- Clock <--PartOf-- Face <--RelatedTo--> Part <--RelatedTo--> Heal 