The tunnel has keystones on each side dated 1879. Previously the Haverford and Merion Road crossed the tracks at grade to the west, closer to the Wynnewood station. After the tunnel was completed, Haverford and Merion terminated at N. Wynnewood Ave., which led through the tunnel to the newly opened E. Wynnewood Road, which followed the property lines west from the Philadelphia city line.
We dated the photo by examining the old maps. Wynnewood Road is depicted as "improved" (paved) on the 1908 map; earlier maps do not indicate road surfaces.