The Noctilucent Sphere Interior is an Unexplored Territory in Xenoblade Chronicles X. It is located in southeastern Sylvalum. It is the interior of the massive Noctilucent Sphere, and is home to Pharsis, the Everqueen, the second most powerful enemy in the game. As with all Unexplored Territories, its discovery yields an achievement ("Within the Noctilucent Sphere").