Owencarrow Viaduct, near Cresslough, County Donegal (1903-47)
Like ancient standing stones in a desolate valley are the ruined remains of the Owencarrow Viaduct near Cresslough in County Donegal, built by the Londonderry & Lough Swilly Railway Company in 1903 as part of a line from Letterkenny to the coastal fishing town of Burtonport. In 1925 high winds derailed a train on the viaduct. The line finally closed in 1947 and the bridge spans were thereafter removed. The construction is in part masonry and in part iron cassions. Here is the map link.