Firth of Tay
The Firth of Tay (Scottish Gaelic: Linne Tatha) is a firth in Scotland between the council areas of Fife, Perth and Kinross, the City of Dundee and Angus, into which Scotland's largest river in terms of flow, the River Tay empties. The firth has a maximum width of at Invergowrie.
River Tees
Emerging from the reservoir at Cauldron Snout the river traverses a series of hard black basalt and dolerite rocks that intrude through the softer limestone, in a succession of falls or rapids. From this point downstream the Tees forms the boundary between the traditional counties of Durham and Yorkshire almost without a break, although since 1974 much of it lies wholly in Durham. The dale widens below Cauldron Snout, and trees appear, contrasting with the broken rocks where the water descends over High Force. After a short turn northwards, the river continues to meander south-easterly. Close to where the B6277 road begins to run parallel to the river is the High Force waterfall. About downstream is the smaller Low Force waterfall.
The scenery becomes gentler and more picturesque as the river descends past Middleton-in-Teesdale (Durham). This locality has lead and ironstone resources. Just to the east of Middleton-in-Teesdale, the River Lune joins the Tees. After passing the village of Romaldkirk to the west, the river is joined by the River Balder at Cotherstone. The ancient town of Barnard Castle, Egglestone Abbey, and Rokeby Park, well known through Sir Walter Scott's poem, are all passed. At Rokeby the Tees is joined by the River Greta. From the area near Eggleston, the river is crossing over millstone grit. From here the valley begins to open out, and traverses the rich plain east and south of Darlington in large meandering curves.