California, Cincinnati is a small neighborhood in the city of Cincinnati, also commonly called Grove Park, after Coney Island's original name. It is located at the confluence of the Little Miami River and Ohio River. Because of this, many of its historical homes have water damage. It is not uncommon to see a home with two or three stories only being inhabited on the uppermost story. It is also the location of the Greater Cincinnati Water Works' main treatment plant. California borders the Cincinnati neighborhoods of Mt.