A place where two rivers meet.

The confluence of two headwaters to make the Ohio River at Pittsburgh, Pennsylvania.

Many confluences have been the sites of important towns and cities, because of their good natural route advantages. Among confluence cities are Pittsburgh (confluence of two tributaries to form the Ohio), and Koblenz (confluence of the Rhine and Mosel, Germany).

The confluence of the Rhine with the Mosel, its largest tributary at Koblenz, Germany.