SB 5.20.36
lokaloka iti samakhya yad anenacalena lokalokasyantarvar-tinavasthapyate.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Between the lands inhabited by living entities and those that are uninhabited stands the great mountain which separates the two and which is therefore celebrated as Lokaloka.