Watertown is a city in Jefferson County, New York, United States. It is located on the northern border of the state, on the Black River. The city has a population of approximately 26,705 residents. Watertown is known for its historic downtown area, which features a variety of shops, restaurants, and cultural attractions. The city is also home to several military installations, including Fort Drum, which is one of the largest Army bases in the country. Watertown offers a range of outdoor recreational opportunities, with nearby attractions including the Thousand Islands region, the Adirondack Mountains, and Lake Ontario.