Financial is related to Rich. Rich is related to Fun. Fun is the opposite of Play. Play is a type of Exploit. 
you are likely to find Sidewalk in/at/on Ground. Ground is a type of Surface. 
Financial <--RelatedTo--> Rich <--RelatedTo--> Fun <--Antonym--> Play --IsA--> Exploit 
Sidewalk --AtLocation--> Ground --IsA--> Surface 