Keystone Earth is one of the infinite number of parallel universes making up the multiverse, and is one of two universes (along with All-world) in which death is final and permanent.

Keystone Earth is the universe which the readers of Stephen King's The Dark Tower series would recognize as "the real world." It includes King himself as the author of the Dark Tower novels, and is the universe in which the Dark Tower itself is represented by a rose growing in a vacant lot in New York City.

Eddie Dean, Susannah Holmes, and Jake Chambers were all drawn from Keystone Earth into All-world in order to join the ka-tet of Roland Deschain.



Keystone Earth is a reference to the term Earth Prime, but it has no relation to Prime Earth.