The boundary line between the two counties is drawn lengthwise down the centre of the lake and is continued down the river Shiel to the sea.
For fully three-fourths of its length Loch Shiel has a south-westerly direction, but at Eilean Fhianain (Finnan's Island) it strikes towards the west.
It receives the Finnan and other small streams and discharges by the Shiel to the salt-water Loch Moidart.
Other important longitudinal lakes are Lochs Tay, Awe, Ericht and Shiel.
Glenfinnan is on the shores of Loch Shiel and is a great vacation place where you have a good chance of spotting golden eagles.