Dun Well Pit. Part of Rainton Colliery, which was opened before 1815 and closed in July 1978. Owners were the North Hetton Coal Company (Earl of Durham, Messrs Wood, Philipson, Burrell and others) and Lady FA Vane Londonderry and the Marquess of Londonderry. Rainton Colliery included Adventure Pit (NZ 315 470), Alexandrina Pit (HER 3219), Hazard Pit (HER 3212), Meadows Pit (HER 6848), Nicholson's Pit (HER 3201), North Pit (HER 3197), Plain Pit (HER 3198), Resolution Pit (NZ 311 476). In 1790 a boring had been put down in South Pit in East Rainton by a Mr Rawlings, to a depth of 10 fathoms. Whellan reported that in 1894 Rainton Colliery had 31 stationary engines, 38 boilers, 1185 workers and 835 workmen's houses. The shaft may have been used as a ventilation shaft for the Hazard Colliery. Its pump house existed into the 20th century.