The River Forth is a major river in central Scotland, 47 km (29 mi) long, which drains into the North Sea on the east coast of the country.
The Forth rises in the Trossachs, a mountainous area 30 km (19 mi) west of Stirling. Ben Lomond’s eastern slopes drain into the Duchray Water, which meets with Avondhu River coming from Loch Ard. The confluence of these two streams is the nominal start of the River Forth.
From there it flows roughly eastward through Aberfoyle, joining with the Kelty Water about 5 km further downstream.
It then flows into the flat expanse of the Carse of Stirling, including Flanders Moss. Just west of the M9, it is joined by the River Teith (which itself drains Loch Venachar, Loch Lubnaig, Loch Achray, Loch Katrine, and Loch Voil).
The next tributary is the Allan Water, just east of the M9. From there the Forth meanders into the ancient port of Stirling.
At Stirling the river widens and becomes tidal.
This is the location of the last (seasonal) ford of the river. From Stirling, the Forth flows east, accepting the Bannock Burn from the south before passing the town of Fallin. It then passes two towns in Clackmannanshire: firstly Cambus (where it is joined by the River Devon), closely followed by Alloa. Upon reaching Airth (on the river\'s south shore) and Kincardine (on its north shore), the river begins to widen and becomes the Firth of Forth.
