Crank Caverns is the common name of what is in fact the remains of the Rainford Delph Quarry. It is a network of underground tunnels and caverns, as well as an extensive woodland. Information in the St. Helens local history archives states that mining began here as early as 1730, with a small stone quarry known as Rainford Delph.
A bit of history can be found here
http://en.wikipedia.org/wiki/Crank_Caverns
My favorite bit being the Myths and Legends surrounding it.
One of the famous Local Myths was the story of the children who went down Crank Caverns in the late 18th century. Four children decided to explore the limestone caverns in the area and vanished. One child survived and told a terrifying tale about small old men with beards who killed his three friends and chased him. The petrified child stumbled over human bones in the caves and finally managed to scramble through an opening to the surface as a hand was grabbing at his ankle. The authorities were concerned because a number of people had gone missing in the area near the cave entrances. Two heavily armed soldiers descended into the caverns with torches and claimed that they not only found a heap of human bones, they also found the ruins of an ancient church of some unknown denomination. The interior of the church was lit by three large candles and grotesque gargoyles formed part of an altar. Throughout the exploration of the underground, the soldiers said they felt as if they were being watched, and also heard voices speaking in an unknown language. One report said that a child's head was found in a cave, along with evidence of cannibalism. After a second investigation, the caves either collapsed or gunpowder was used to seal them, and so the riddle of the underground church of Crank Caverns remains unsolved.