Outside the ocean of yogurt is another island, known as Puṣkaradvīpa, which is 6,400,000 yojanas [51,200,000 miles] wide, twice as wide as the ocean of yogurt. It is surrounded by an ocean of very tasteful water as broad as the island itself. On Puṣkaradvīpa there is a great lotus flower with 100,000,000 pure golden petals, as effulgent as the flames of fire. That lotus flower is considered the sitting place of Lord Brahmā, who is the most powerful living being and who is therefore sometimes called bhagavān.
(Srimad Bhagavata,------5:20:29------translation).

Thereafter, beyond the ocean of sweet water and fully surrounding it, is a mountain named Lokāloka, which divides the countries that are full of sunlight from those not lit by the sun.
(Srimad Bhagavata,------5:20:34------translation).

Beyond the ocean of sweet water is a tract of land as broad as the area between the middle of Mount Sumeru and the boundary of Mānasottara Mountain. In that tract of land there are many living beings. Beyond it, extending to Lokāloka Mountain, is another land, which is made of gold. Because of its golden surface, it reflects light like the surface of a mirror, and any physical article that falls on that land can never be perceived again. All living entities, therefore, have abandoned that golden land.
(Srimad Bhagavata,------5:20:35------translation).

From Śrīmad-Bhāgavatam we understand that there are various oceans. Somewhere there is an ocean filled with milk, somewhere an ocean of liquor, an ocean of ghee, an ocean of oil, and an ocean of sweet water. Thus there are different varieties of oceans within this universe. The modern scientists, who have only limited experience, cannot defy these statements; they cannot give us full information about any planet, even the planet on which we live. From this verse, however, we can understand that if the valleys of some mountains are washed with milk, this produces emeralds. No one has the ability to imitate the activities of material nature as conducted by the Supreme Personality of Godhead.
(Srimad Bhagavata,------8:2:4------purport).