Charles Dodgson (Lewis Carroll) moved to Croft Rectory at the age of 11. About a mile from the rectory there are three ponds called Hells Kettles, the local people believed that these pools were bottomless. It has been suggested that the author’s vision of Alice falling down a deep vertical hole into an underground land was inspired by these pools.
The kettles were formed by underground water dissolving gypsum deposits.
read more here
The Smell of Water 