Tay, River, is the longest river in Scotland, flowing 120 miles (193 kilometers) from its source to the North Sea. It rises as the Cononish on Ben Lui in the western part of central Scotland. It flows through Strath Fillan, then continues as the Dochart between mountains into Loch Tay. It becomes the River Tay there and winds through Aberfeldy, Dunkeld, and Perth and into the Firth of Tay.