CULTURE Secretary Jeremy Hunt goes underground tomorrow .

The minister will visit the National Coal Mining Museum, near Grange Moor, to open the newly-conserved furnace shaft and new displays in the lamp room.

When the furnace shaft was found to be in danger of collapse in 2007, the Department for Culture, Media and Sport and the Department of Trade and Industry (DTI) each contributed £150,000 towards its restoration.

This kick-started a successful application to the Heritage Lottery Fund for the eventual cost of £870,000 for conserving the shaft.

The furnace shaft – believed to be the only one still in existence – would originally have had a fire lit at the bottom to send warm air up the shaft, thereby drawing in fresh air down the main riding shaft 35 metres away and so ventilating the pit.

Work to repair the shaft took around eight months while engineers were also called in to find ways to allow visitors safe access into the furnace shaft at its base 140 metres underground.

The shaft now has a glass cover, enabling visitors to look down its full 120-metres depth.