The landscape of south Wales has been shaped and defined by coal. In this programme, Helen Mark explores the Rhondda valley – finding out about is history and asking what its future may look like, now the heavy industry has gone. She visits a disused railway tunnel which once carried coal from the mines to the port of Swansea, but which has been closed and sealed off for decades. Now a group of enthusiasts is campaigning to re-open the tunnel as a tourist attraction. They have ambitions plans for it to become the longest cycling tunnel in Europe, with hopes that it could also function as an exhibition space, miniature concert hall and even a wedding venue. Helen puts on her safety helmet and is lowered down through a shaft into the tunnel, to see for herself how the structures of the past could take on a new life in the future. Produced by Emma Campbell