The Rappahannock River rises at Chester Gap, a wind gap in the Blue Ridge Mountains a few miles southeast of Front Royal, Virginia. It flows southeastward before it is joined by the Rapidan River, its largest tributary, from the right. Then the Rappahannock passes through the city of Fredericksburg. Southeast of Fredericksburg, it begins to slow and widen into a brackish tidal estuary approximately long. It passes two small, but historic, river towns, Port Royal and Port Conway, which sit opposite each other. The former is on the south bank, the latter on the north. Then it flows past Tappahannock on its southern bank, a point where the river is well over a mile wide. The last settlements of any size before reaching the Chesapeake Bay are Irvington, Urbanna, Stingray Point, and White Stone Beach. The broad river enters the Chesapeake Bay approximately south of the mouth of the Potomac River and approximately east of the state capital, Richmond. At the point where the river enters the bay, between Windmill Point, on the north, and Stingray Point, on the south, it is more than wide. This area, the estuary south of the Northern Neck peninsula, is a productive oyster and crab fishery.