sentences:  Railways appeared very early in this part of Scotland and one of the first built was the stone viaduct over the Irvine at Laigh Milton, part of the Kilmarnock and Troon Railway.It has four arches, and although not used since 1846, it was restored in 1996.The railway carried steam locomotives 9 years before the Stockton and Darlington Railway and is believed to be the first passenger steam railway in the world.