Flat Rock, Ohio
Flat Rock is a census-designated place in northeastern Thompson Township, Seneca County, Ohio, United States. Although it is unincorporated, it has a post office, with the ZIP code of 44828.History
Flat Rock was originally called Lewisville, and under the latter name was platted in 1841. A post office called Flat Rock has been in operation since 1846. The present name comes from a flat layer of rock covering an artesian aquifer.
