The Chain Bridge Tunnel is a tunnel at Berwyn Station and was built in the nineteenth century to provide access to the Chain Bridge across the River Dee.

The station is on the Ruabon to Barmouth Line, a standard gauge branch line of the Great Western Railway that connected Ruabon in the east to Barmouth on the west coast of Wales.

The graffiti in this tunnel is purported to have been created by First World War soldiers travelling on the railway. Most of the graffiti appears to have been created using pencil on the brickwork.

I.N.Wright, RCAHMW, 18 March 2011.