Doing a bit of research on Riversley Park to gather more local knowledge before venturing out I was surprised to find "Secrets of Nuneaton" and scrolling down I find reference to the Riversley Railway Tunnel. Getting momentarily excited I thought "Oooh, wonder what's in there?" to find it is more like "What WAS in there?" Resin bricks, each containing silk ribbon which was woven here since the 17th century and some made reference to works of art inspired by life in Nuneaton. But, thanks to repeated efforts by vandals "The Secrets of Nuneaton" have been removed from the tunnel and it would seem that currently, the only way to view the work is by photos on the website:

Sustrans Secrets of Nuneaton

If you want to know more about Ribbon weaving in Nuneaton you must listen to John Burton.
He has researched it and still is doing so. Watch out for his talks . Ithink he has a book coming out soon.
You can get information from the Museum.
I know John and went to his George Eliot lectures- and he is so entertaining .

Shame that vile scum have to ruin what we decent people puta lot of effort in to isn't it shiz