Srimad Bhagvata Mahapurana: Book 5: Chapter 16: Verses 1-11
A description of the terrestrial world
The king (Pariksit) said : You have described the extent of the terrestrial globe as covering the whole range where the sun shines and where, on the other hand, the yonder moon with the host of (other) heavenly bodies is visible. Within that very extent are comprised the seven oceans formed by the seven furrows dug by the (revolving) wheels of the chariot of Emperor Priyavrata; and it is to these (oceans) indeed that you have ascribed, O glorious sage, the division of the earth into seven distinct Dwipas (subdivisions). I have a desire to know all this in detail with the extent and characteristic features (of the various divisions, the oceans and soon). For, (when) focussed on the Lord's gross material form (in the shape of this universe) the mind becomes (gradually) fit to be concentrated on the immaterial, most subtle (hard to perceive), self-effulgent and transcendent Brahma (the Infinite), known by the name of Lord Vasudeva.
Therefore, be pleased to describe the same, O (my) preceptor ! The sage (Sri Suka) replied : No man, O great king, can ever succeed in ascertaining with his mind, much less (describing) in words, the full extent of the vast display (in the form of the universe) set up by the Gunas of the Lord's Maya (deluding potency) even if he strives for a whole lifetime of the gods. Therefore, we propose to discuss at length only the salient features of the terrestrial globe with the names, position, extent and characteristics of the various subdivisions. As for this (particular) Dwipa (the one inhabited by us), it represents the innermost of the (seven) sheaths of the lotus-like terrestrial globe, with a diameter of one lakh Yojanas (8,00,000 miles) and round (in shape) like the corolla of a lotus. In this Dwipa are comprised nine Varsas (subdivisions of a Dwipa)- each nine thousand Yojanas (72,000 miles) in extent-clearly divided by eight mountain ranges which form their (natural) boundaries. In the middle of these continents stands the inner Varsa, called Ilavrta, at the centre of which is situated the king of (all principal) mountain ranges, Meru (Sumeru), entirely consisting of gold and possessing a height equal to the extent of the Dwipa (viz., one lakh Yojanas). It forms the pericarp of the lotus-like terrestrial globe and has a diameter of thirty-two thousand Yojanas (2,56,000 miles) at the top and (only) sixteen thousand Yojanas (1,28,000 miles) at the foot, with its root lying under the earth's surface to a depth of sixteen thousand Yojanas. (That is to say, the mountain is only eighty-four thousand Yojanas high above the earth's surface). (7) To the north of Ilavrta are situated one after another the three mountain ranges called Nila, Sweta and Srngavan, severally forming the boundaries of the Varsas bearing the names of Ramyaka, Hiranmaya and Kuru and extending east and west as far as the salt ocean, each two thousand Yojanas (16,000 miles) wide and every exterior range being shorter in length alone by a little over one-tenth of the next interior range (but equal in height and breadth).
Likewise to the south of Ilavrta, and extending from east to west, stand the (three mountain ranges called) Nisadha, Hemakuta and Himalaya--each possessing a height of ten thousand Yojanas (80,000 miles)and severally marking the boundaries of Harivarsa, Kimpurusavarsa and Bharatavarsa. Even so to the west and east of Ilavrta stand the (mountain ranges of) Malyavan and Gandhamadana respectively, severally extending as far as the Nila mountain (on the north) and the Nisadha mountain (on the south) and covering a breadth of two thousand Yojanas (16,000 miles) each. They mark the boundaries of (the Varsas called) Ketumala and Bhadraswa (respectively). On the four sides of Mount Meru stand the Mandara, Merumandara, Suparswa and Kumuda mountains, forming its buttresses (as it were), and having a length and height of ten thousand Yojanas (80,000 miles).