"He lives here? Here? In this Muggle dunghill? We must be the first of our kind ever to set foot--"
-- Bellatrix Lestrange upon Apparating into Cokeworth (HBP2)
Cokeworth is a midlands town where Lily and Petunia Evans grew up (Pm). It is also the home of Severus Snape and his family (DH33), and until 1998 Snape still lived in his parents old house there (HBP2, Pm). Other Cokeworth locations of note include the Railview Hotel, where Vernon Dursley drove the family in a desperate attempt to escape Harry’s letters from Hogwarts (PS3) and a playground where a young Lily Evans learned from “that awful boy” (as Petunia called Snape) that she was a witch (DH33).
It's quite ironic (and stupid on Vernon's part) that the Dursleys fled to Cokeworth to avoid Harry's Hogwarts letters since that's where Lily and Severus received their own Hogwarts Letters (with Petunia left out). You can't outrun the Owl Post. And indeed, "hundreds" of the letters arrive for Harry at the Railview Hotel.