Turtleback Lane is a road in Maine of the Keystone World. It was the center of the Walk-in activity. This is due to the fact that the fabric of reality is thin at that location. Stephen King eventually moved to live on the Nineteenth house on the street, a house called Cara Laughs.
Cara Laughs is where Roland Deschain and Eddie Dean travel back to the corridor and door under the Dixie Pig and confront Flaherty and the group of vampires, taheen and Low Men that had been chasing Jake Chambers and Oy.