The River Tay (Gaelic: Tatha) is the longest river in Scotland having a length of 120 miles (193 kilometres) The Tay originates in western Scotland on the slopes of Ben Lui, then flows easterly across the Highlands, through to the Firth of Tay in the centre of Scotland, then south easterly through Perth, where it becomes tidal.
The River Forth (Gaelic: Abhainn Dubh, meaning “black river”). The River Forth is 29 miles (47 kilometres) long is the major river in eastern central Scotland.
The River Clyde (Gaelic: Abhainn Chluaidh) which is the second longest river in Scotland at 109 miles (176 Kilometres) and flows through Glasgow, Scotland’s largest city. Its source is in the Lowther Hills in South Lanarkshire before finishing at the mouth of the Clyde.
The River Tweed(Gaelic Abhainn Thuaidh : ‘North’) is 97 miles (156 kilometeres) long and flows across the Borders. As with the Clyde, the Tweed rises in the Lowther Hills at Tweed Wells before flowing to the North Sea.
The River Ness(Gaelic Abhainn Nis) is 12 miles(20 kilometres long) flows from the northern end of Loch Ness to the city of Inverness then in to the Beauly Firth.
The River Dee(Gaelic Uisge Dhe) is 87 miles (140 kilometres) long. It rises in the Cairngorms flows through Strathdee to Aberdeen then in to the North Sea.