Lord Krsna took Arjuna through this place (the destination of those who aspire for liberation from the material world, beyond Aloka-varsa) to bring back the sons of the brahmana
SB Canto 5
My dear King, outside Lokāloka Mountain is the tract of land known as Aloka-varṣa, which extends for the same breadth as the area within the mountain—in other words, 125,000,000 yojanas (one billion miles). Beyond Aloka-varṣa is the destination of those who aspire for liberation from the material world. It is beyond the jurisdiction of the material modes of nature, and therefore it is completely pure. Lord Kṛṣṇa took Arjuna through this place to bring back the sons of the brāhmaṇa.