troon
Irvine is a town in North Ayrshire, Scotland and is located on the coast of the Firth of Clyde.
The Antonine Wall is between Firth of Forth and Firth of Clyde.
bay
The Antonine Wall is in Scotland, between the Firth of Forth and the Firth of Clyde.
arron
The Antonine Wall is in Scotland, between the Firth of Forth and the Firth of Clyde.
Source - Lowther Hills in South Lanarkshire. Mouth - Firth of Clyde
Between 50 and 150 meters
Ayrshire
The Clyde and Forth place river is not a recognized river name; however, the River Clyde and the Firth of Forth are two significant water bodies in Scotland. The River Clyde flows through Glasgow and into the Firth of Clyde, while the Firth of Forth is an estuary that opens into the North Sea, bordered by cities like Edinburgh and Fife. These two rivers are important for Scotland's geography, economy, and maritime activities.
Dunoon is a resort town on the Cowal Peninsula in Argyll, Scotland. Dunoon sits on the Firth of Clyde to the south of Holy Loch and to the west of Gourock.
I'm guessing it might just be the Clyde ! It's the main river which flows through Glasgow.