“Near the camp is Hill Hole or Hell Hole Dingle, locally Hello Dingle*. This is said to have been named after the holy well at Pencombe, whose water meets the Humber Brook near the spot, but it is more likely that there was a holy well at Hollywell or Hollywall Farm on the old Roman road above the dingle.”
From “The Healing Wells of Herefordshire” – Jonathan Sant (1994 Moondial).
*On the OS 1:25000 (2006 ed) this is shown as “Hill Hole”, at SO537542.