Thomas also tells Anton that the seventh level of the Twilight is the Others' paradise, where they can exist in peace together (upon death, Others just vanish into the Twilight). Merlin has hidden the Crown of All Things in the seventh level of the Twilight.
The seventh level of the Twilight is designated as the Others' paradise, a location where they can coexist peacefully (after death, the Others simply disappear into the Twilight). Merlin has concealed the Crown of All Things within this same level.