Torpenhow Hill.
When the Saxons arrived and asked the Welsh the name of that hill, the Welsh said "pen" which means "hill" in Welsh. So the Saxons used their word for hill, "tor," and called it Torpen (hill hill).
Then the Norse arrived and the same process added the their world for hill "Haugr". So now it was Torpen Haugr (Hill Hill Hill).
Later, the English called it Torpenhow Hill (Hill Hill Hill Hill)