Firth of Forth

The Firth of Forth, near Edinburgh.

"Firth" is a term used primarily in Scotland to describe usually a long narrow estuary, often a fjord, and sometimes a strait. The best known are those of the Forth, Tay, and Clyde; the Solway Firth, into which several rivers drain; the Moray Firth, between the northeast tip of Loch Ness and the North Sea; and the Pentland Firth, the strait between northeast Scotland and the Orkney Islands.