The Puranic description of the geography of Earth is full of fabulous elements. For example,

“Earth, composed of seven continents, together with the oceans extends 500,000,000 leagues across. Holy Jambudvipa lies in the middle of all the continents; in its centre is said to be lofty Mt. Meru, bright as gold. Its height is 84,000 leagues, and it extends 16,000 leagues below the earth; its width at the top is 32,000 leagues, and its diameter at the base is 16,000 leagues”.

Kurma Purana, in Classical Hindu Mythology, p. 52.

In this quote, " league" is presumably a translation of a Sanskrit term at least loosely approximating the usual English meaning of " league" (about three miles). At this rate, Mt. Meru is something like 252,000 miles high. The tallest actual mountain on Earth is Mt. Everest, at about 29,000 ft, or less than six miles.

In the next quote we see that the impossibly high Mt. Meru is held to be the source of really existing rivers in India such as the Sita:

“Ganga, the heavenly river flowing from the feet of Visnu and inundating the orb of the moon, falls all around the city of Brahma. Falling on the four regions, O twice-born ones, she subdivides into four rivers, namely Sita, Alakananda, Sucaksus and Bhadra. The river Sita flows from the atmosphere east of Mt. Meru and then through the eastern range called Bhadrasva to the sea. And each of the others does likewise: Alakananda to the South enters Bharatavarsa; Sucaksus to the West falls on Ketumala, and Bhadra to the North falls through Uttarakuru...”

Kurma Purana, in Classical Hindu Mythology, p. 54

The scripture then describes nine different subcontinents, of which one (Bharatavarsa) includes or is the same as India. Eight of the subcontinents are populated by people who live paradisial lives.

Astronomy

“Bhurloka, Bhuvarloka, Svarloka, Maharloka, Janaloka, Taparloka and Satyaloka are the worlds thought to have their origin in the egg. In the old stories Bhurloka is said to stretch out as far as sun and moon radiate their beams of light, O bulls of the twice-born. As far as Bhurloka extends in width and circumference, so does Bhuvarloka spread out from the sphere of the sun, from which sphere the firmament extends upward as far as Dhruva is located. This region is called Svarloka... The sphere of the sun lies 100,000 leagues from earth. The orb of the moon is also said to be 100,000 leagues from the sun. The whole circle of naksatras appears the same distance from the moon. Twice this distance beyond the naksatras, O wise ones, is the planet Budha (Mercury), and Usanas (Venus) dwells the same distance from Budha. Angaraka (Mars) too is the same distance from Sukra (Venus). The priest of the gods (Brhaspati/Jupiter) resides 200,000 leagues from Bhauma (Mars), while Sauri (Saturn) is the same distance from the guru (Jupiter). This is the sphere of the planets. The sphere of the Seven Seers shines 100,000 leagues' distance from that. Dhruva dwells the same number of leagues above the sphere of the seers. Dhruva is the central point of this entire wheel of luminaries in which resides the lord Dharma, Visnu Narayana”.

Kurma Purana, in Classical Hindu Mythology, pp. 46-47.

The notion that the distance from the earth to the sun is the same as the distance from the sun to the moon. Actually, the distance between earth and sun is vastly greater than the distance from the sun to the moon.

The stars in the naksatras (lunar constellations) are said to be closer to us than are several of the planets; but actually, all stars are vastly more distant from us than all planets. The listed distances between the planets are neither accurate nor even proportional to their actual distances. The stars in the Little Dipper are said to be proportionally only slightly further from us than Saturn, whereas actually they are vastly more distant.

In addition to the inaccuracies, there is the strange omission of all mention of the outer planets (Uranus, Neptune, and Pluto). This omission is easy to understand if you suppose the Hindu astronomy was based on naked-eye observations; much more difficult if you suppose that such knowledge come from the infallible psychic insight of great rishis”.