|This is an old revision of this page, as edited by Rambler24 at 03:12, 26 October 2009 (C.Michael Hogan is not a recognised source. Hadrian's Wall crosses the Irthing at Birdoswald.). The present address (URL) is a permanent link to this revision, which may differ significantly from the .|
|- location||Paddaburn Moor|
|- location||confluence with River Eden|
Rising in the hills around Paddaburn Moor in Border Forest Park, for the first 15 miles of its journey south it defines the border between Northumberland and Cumbria. After passing Butterburn Flow raised bog, the river flows over the ten-metre high Crammel Linn waterfall in a sandstone gorge. At Gilsland Spa, a sulphurous spring oozes out of the gorge walls. Chalybeate and petrifying springs are also characteristic of the local geology and are found on the Irthing's banks.
The River Irthing marked a significant transition in construction of Hadrian's Wall, between the limestone to the east and sandstone to the west. Hadrian's Wall crossed the river on a bridge at Willowford, east of Birdoswald Roman Fort. The fort is situated above a steep gorge carved by the river from the deep glacial till overlying the area. From that point its course as it turns west is lined with other Roman sites associated with the Roman Stanegate road and Hadrian's Wall,
- Philip's Motorist's Atlas: 2004, Octopus Publishing Group, London, England
- English Lakes: River Irthing