Pen Park Hole was reopened in February 1992. This allowed new studies to be made of its geomorphology and in addition further researches into its history were conducted. It is concluded that the cave was first discovered in 1669 and first explored in that year. It has never been commercially mined, although several investigations were made by miners. The cave is considered to be of hydrothermal origin and to be much older than the nearby Mendip caves, probably being active in late Triassic, early Jurassic times.