tathaivelavrtam aparena purvena ca malyavad-gandhamadanav anila-nisadhayatau dvi-sahasram paprathatuh ketumala-bhadrasvayoh simanam vidadhate.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In the same way, west and east of Ilavrta-varsa are two great mountains named Malyavan and Gandhamadana respectively. These two mountains, which are 2,000 yojanas [16,000 miles] high, extend as far as Nila Mountain in the north and Nisadha in the south. They indicate the borders of Ilavrta-varsa and also the varsas known as Ketumala and Bhadrasva.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
There are so many mountains, even on this planet earth. We do not think that the measurements of all of them have actually been calculated. While passing over the mountainous region from Mexico to Caracas, we actually saw so many mountains that we doubt whether their height, length and breadth have been properly measured. Therefore, as indicated in Srimad-Bhagavatam by Sukadeva Gosvami, we should not try to comprehend the greater mountainous areas of the universe merely by our calculations. Sukadeva Gosvami has already stated that such calculations would be very difficult even if one had a duration of life like that of Brahma. We should simply be satisfied with the statements of authorities like Sukadeva Gosvami and appreciate how the entire cosmic manifestation has been made possible by the external energy of the Supreme Personality of Godhead. The measurements given herein, such as 10,000 yojanas or 100,000 yojanas, should be considered correct because they have been given by Sukadeva Gosvami. Our experimental knowledge can neither verify nor disprove the statements of Srimad-Bhagavatam. We should simply hear these statements from the authorities. If we can appreciate the extensive energy of the Supreme Personality of Godhead, that will benefit us.