This bridge spans the river Tweed at the point where it narrows to flow through the rocky defile known as Carlow's Linn, 400 yards SW of Tweedsmuir Church. It is built entirely of rubble masonry and comprises a single arch having a span of 30 feet and a width of 15 feet. Upon the south facing of the bridge a block of sandstone bearing the date of 1783 is built into the fabric above the crown of the arch. The bridge was constructed by James and Alexander Noble who were stone masons based in the Upper Tweed area. The structure evidently replaces the earlier bridge shown on William Edgar's map of peeblesshire, surveyed in 1741.
(The above details are from the Royal Commission survey for Peeblesshire in 1959) Various spellings can be found in the records such as Carlows and Carlowse but the 's version has found favour with both Historic Scotland and the Royal Commission (RCAHMS). I wonder who Mr or Mrs Carlow (Carlaw) was who gave their name to the Linn (waterfall). John Buchan referred to it as Curlew Linn in his short story titled A Sentimental Journey in his early book Scholar Gypsies. Or, is Carlow a corruption of Carlin the Scots word for witch - Witches Linn? This bridge is the sole access for the large lorries taking away the harvested spruce and pine trees from the Tweedsmuir forests. The fact that this ancient bridge designed for a mule and cart can cope with the weight of these lorries is a wonder.
The bridge - March 2011 - is now showing signs of wear and tear and with no sign of the number of timber lorries crossing the bridge diminishing there is real concern by the local residents that the bridge could fail - leaving them isolated. The Scottish Borders Council are aware of the problem but appear to have no solution as to what can be done.