Hazen Cemetery is located along Brass Castle Road in Belvidere (or two other web searches list White Township and Oxford).Needless to say, it is located in that area of Warren County. Since I really do not know anything about Warren County, I hope it’s a good enough answer.
Back to Hazen Cemetery details: It is a smaller cemetery, but well maintained and contains several Civil War soldier graves along with veterans of other wars. The retaining wall has a stone block with “1848” carved into it (see picture below, please) and it seems there have been relatively recent burials in the past decade. This cemetery doesn’t seem to hold any specific historical significance either. I vaguely remember some kind of farm across the street, but specifically remember there is no parking lot. You have to park on the grass and make sure you are far enough in from the road.