Question: What is a city in the state of New York and the county seat of Jefferson County, that has  a junction with U.S. Route 11 and NY 12?

Context paragraphs:
New York State Route 180: New York State Route 180 (NY 180) is a north–south state highway in the northwestern part of Jefferson County in the U.S. state of New York.  The southern terminus of the route is at NY 3 in the Hounsfield hamlet of Baggs Corner, located 7 mi west of downtown Watertown.  The northern terminus is at NY 12 in the Orleans hamlet of Fishers Landing.  NY 180 is part of the Seaway Trail from its southern terminus at Baggs Corner to its junction with NY 12E at the Brownville hamlet of Limerick.

New York State Route 283: New York State Route 283 (NY 283) is an east–west state highway in Jefferson County, New York, in the United States.  It extends for 5.79 mi as a two-lane road from an intersection with U.S. Route 11 (US 11), NY 3, and NY 12 in downtown Watertown to a junction with NY 342 in the town of Le Ray.  The route passes through mostly rural areas, with the exception of a dense commercial district around the highway's west end.  NY 283 is one of three routes directly connecting Watertown's Public Square to Fort Drum; the others are US 11 and NY 3, which loosely parallel NY 283 between the two locations.

New York State Route 12D: New York State Route 12D (NY 12D) is a north–south state highway located in the northern part of New York in the United States.  The southern terminus of the route is in the Oneida County village of Boonville, where it intersects NY 12.  The northern terminus is at a junction with NY 12 in the Lewis County village of Lyons Falls.  NY 46 and NY 294 are also present in the immediate area of the route's southern terminus.

New York State Route 12E: New York State Route 12E (NY 12E) is a state highway located entirely within the northwestern part of Jefferson County in northern New York in the United States.  The southern terminus is at NY 12F in the village of Brownville.  Its northern terminus, both signed and official, is at NY 12 in the village of Clayton.  While NY 12 follows a direct north–south routing between Watertown and Clayton, NY 12E diverges westward to follow the shoreline of Lake Ontario.  The portion of NY 12E north of its junction with NY 180 is part of the Seaway Trail, a National Scenic Byway.

New York State Route 177: New York State Route 177 (NY 177) is an east–west state highway in the North Country of New York in the United States.  It extends from Interstate 81 (I-81) exit 42 in the Jefferson County town of Adams to NY 12 west of the Lewis County village of Lowville.  NY 177 intersects U.S. Route 11 (US 11) in Adams Center and meets Lewis County's County Route 21 (CR 21), formerly part of NY 194, at Barnes Corners.  NY 177 originally began at US 11 when it was assigned in 1930.  It was extended west to its present terminus in the 1950s following the construction of I-81.

New York State Route 342: New York State Route 342 (NY 342) is a short east–west state highway in Jefferson County, New York, in the United States.  The western terminus of NY 342 is at an intersection with NY 12 near the hamlet of Scoville Corners in the town of Pamelia.  The eastern terminus is at a junction with NY 3 in the town of Le Ray, west of the village of Black River.  Along the way, NY 342 connects to Interstate 81 (I-81) in Pamelia and intersects U.S. Route 11 (US 11) outside of the Le Ray hamlet of Calcium.

New York State Route 12F: New York State Route 12F (NY 12F) is an east–west state highway in Jefferson County, New York, in the United States.  It extends for 6.89 mi from an intersection with NY 180 in the town of Hounsfield to a junction with U.S. Route 11 (US 11) and NY 12 in the city of Watertown.  The route follows a parallel routing to that of NY 12E between the vicinity of the village of Dexter and the city of Watertown.  While NY 12E runs along the north side of the Black River through this area, NY 12F follows the southern bank.  Just east of NY 180, NY 12F serves Watertown International Airport.

New York State Route 178: New York State Route 178 (NY 178) is an east–west state highway in Jefferson County, New York, in the United States.  It extends for 10.23 mi from an intersection with NY 3 by Aspinwell Corners in the town of Henderson to a junction with U.S. Route 11 (US 11) in the village of Adams.  NY 178 meets Interstate 81 (I-81) at exit 41 0.5 mi west of its junction with US 11.  When NY 178 was assigned in the 1930 renumbering of state highways in New York, it continued east along modern County Route 189 (CR 189) to NY 177 in Rodman.  This extension was eliminated in 1979.  From the early 1930s to the late 1960s, NY 178 also continued west toward Lake Ontario on what is now County Route 178.

Watertown (city), New York: Watertown is a city in the state of New York and the county seat of Jefferson County.  It is situated approximately 20 miles (35 km) south of the Thousand Islands, and 70 miles north of Syracuse, New York.  As of the 2010 census, it had a population of 27,023, an increase of 1.2% since 2000.  The U.S. Army post Fort Drum is near the city.

New York State Route 12B: New York State Route 12B (NY 12B) is a state highway in the central part of New York in the United States.  NY 12B is a north–south highway connecting Oneida County in the north to Chenango County in the south, passing through Madison County in between.  The southern terminus of NY 12B is at NY 12 in the village of Sherburne.  The northern terminus is at NY 5 in the town of New Hartford.  In Madison County, NY 12B directly abuts the campus of Colgate University in the village of Hamilton.

Supporting paragraphs: New York State Route 12F Watertown (city), New York
Answer: Watertown