 Under the management of the Duke's overseer, Frank Redfern, the entrance was widened and, in 1859, a system of gas lamps was installed to light the caverns (one of the earliest uses of gas in this context), which remained in use until the cave closed in 1965.It reopened in 1976.The region currently open to the public is around in length, and includes chambers named the Roman Chamber, Great Dome, Poached Egg Chamber and Sculpture Chamber.