Claim: Perth Bridge, designed in an arch, crosses over the River Tay, the longest river in Scotland.
Evidence: Perth Bridge (also known as Smeaton's Bridge, locally, the Old Bridge, and in the local dialect of Scots, "the Auld Brig") is a toll-free bridge in the city of Perth, Scotland. It spans the River Tay, connecting Perth, on the western side of the river, to Bridgend, on its eastern side, carrying both automotive and pedestrian traffic of West Bridge Street (the A85). River Tay Perth, Scotland Arch 
The River Tay (Scottish Gaelic: Tatha, IPA:[ˈt̪ʰahə]) is the longest river in Scotland and the seventh-longest in the United Kingdom.