The Shannara series is set in a post-apocalyptic world called the Four Lands. This world is a futuristic version of our own, and not a secondary world. The Genesis of Shannara trilogy reveals the Four Lands to be located in the modern Pacific Northwest region of the United States and Canada. Much of the landscape has been changed by a future atomic war holocaust called The Great Wars, but some landmarks remain. For example, the Columbia River still exists.