Islington is a neighbourhood in Greater London, England, and forms the central district of the London Borough of Islington. Islington was the location of the cave in which Arthur Dent lived during Earth's prehistoric period Two million years later, exactly the same spot was the location of Fenchurch's home.
Behind the scenes
Douglas Adams himself spent a great deal of time with friends in the borough, especially when bouncing a number of his earliest iterations of stories around. He dedicated his novel The Hitchhiker's Guide to the Galaxy to the Arlingtonians, for tea and sympathy.