17:40The Marble Arch Caves: An Underground Journey in County FermanaghBBC One Northern Ireland Duration: 30 minutes Mon 25th Aug 1986, 17:40 on BBC Two Northern IrelandThe choir of Rathmore Grammar School, Belfast, takes a musical tour of the Marble Arch Caves in County Fermanagh with geologist Philip Doughty and caver Tim Fogg. Source: BBC Online