PENARTH’S HIDDEN & FORGOTTEN SUBMARINE SUBWAY IS RE-APPRAISED
An extraordinary 21st century analysis of one of Penarth’s major – but unsung – engineering triumphs, the long-forgotten pedestrian tunnel beneath the River Ely, has now revealed…
Source: PENARTH’S HIDDEN & FORGOTTEN SUBMARINE SUBWAY IS RE-APPRAISED
willmacmillanjones 
My mother walked under that tunnel as child she never called it a subway just tunnel
Has she any photos Julie?
No it was over 70 years ago but there are photos in old Penarth books
Grangetown members of Penarth Sea Cadets in the 50s and early 60s went 2,3, and occasionally 4 days a week back and fore to Penarth Dock and beyond via the subway during the summer and autumn days. In the darker nights we caught a train there and back. There used to be a piggery on the Grangetown side of the subway which used to smell terribly