Walnut Tree Viaduct at Tongwynlais carried the Barry Railway branch line across the Taff Valley and on to Llanbradach in the Rhymney Valley. It was 1,500 feet long and 130 feet high. Math Eitemau Uwchlwytho gan Pontypridd Museum
Taff Valley: Map/Figure Math Eitemau Uwchlwytho gan 'A Dedicated Naturalist', the Mary Gillham Archive Project
