The county seat of Suffolk County, NY lies at the mouth of a river that flows into which body of water?
Riverhead (town), New York: Riverhead is a town within Suffolk County, New York, on the north shore of Long Island. Riverhead (town), New York:  The town rests on the mouth of the Peconic River, from which it derives its name. Riverhead (town), New York:  Since 1727, Riverhead has been the county seat of Suffolk County. Peconic River:  The Peconic River drains an area between the Harbor Hill and Ronkonkoma terminal moraines, and flows into Flanders Bay which in turn connects to Peconic Bay east of Riverhead.
Flanders Bay