A view of Cefn Viaduct, Wrexham, submitted by contributor Simon Mapp from Wrexham. Simon took the photo from Ty Mawr Country Park. From checking archives at Wrexham Museum, Simon found that the viaduct was built by Thomas Brassey, at the instigation of Henry Robertson, founder of the North Wales Mineral Railway. It took two years to build, costing £72,346, and is 1,508 feet long, 147 feet high, and has 19 stone arches. It was officially opened on August 14 1848, with the first train - with Mrs Robertson as the conductor - going over it on October 2. The first public train went across on October 12, and was 20 carriages long.