Bharatvarsha's geographical extent,its ethno cultural regions, tribes, rivers, mountains as described in Mahabharta by Sanjaya.
http://www.sacred-texts.com/hin/m06/m06009.htm
From Srimad Bhagvatam
In the tract of land known as Bhārata-varṣa, as in Ilāvṛta-varṣa, there are many mountains and rivers. Some of the mountains are known as Malaya, Maṅgala-prastha, Maināka, Trikūṭa, Ṛṣabha, Kūṭaka, Kollaka, Sahya, Devagiri, Ṛṣyamūka, Śrī-śaila, Veṅkaṭa, Mahendra, Vāridhāra, Vindhya, Śuktimān, Ṛkṣagiri, Pāriyātra, Droṇa, Citrakūṭa, Govardhana, Raivataka, Kakubha, Nīla, Gokāmukha, Indrakīla and Kāmagiri. Besides these, there are many other hills, with many large and small rivers flowing from their slopes. Two of the rivers — the Brahmaputra and the Śoṇa — are called nadas, or main rivers. These are other great rivers that are very prominent: Candravasā, Tāmraparṇī, Avaṭodā, Kṛtamālā, Vaihāyasī, Kāverī, Veṇī, Payasvinī, Śarkarāvartā, Tuṅgabhadrā, Kṛṣṇāveṇyā, Bhīmarathī, Godāvarī, Nirvindhyā, Payoṣṇī, Tāpī, Revā, Surasā, Narmadā, Carmaṇvatī, Mahānadī, Vedasmṛti, Ṛṣikulyā, Trisāmā, Kauśikī, Mandākinī, Yamunā, Sarasvatī, Dṛṣadvatī, Gomatī, Sarayū, Rodhasvatī, Saptavatī, Suṣomā, Śatadrū, Candrabhāgā, Marudvṛdhā, Vitastā, Asiknī and Viśvā. The inhabitants of Bhārata-varṣa are purified because they always remember these rivers. Sometimes they chant the names of these rivers as mantras, and sometimes they go directly to the rivers to touch them and bathe in them. Thus the inhabitants of Bhārata-varṣa become purified.
The people who take birth in this tract of land are divided according to the qualities of material nature — the modes of goodness [sattva-guṇa], passion [rajo-guṇa], and ignorance [tamo-guṇa]. Some of them are born as exalted personalities, some are ordinary human beings, and some are extremely abominable, for in Bhārata-varṣa one takes birth exactly according to one’s past karma. If one’s position is ascertained by a bona fide spiritual master and one is properly trained to engage in the service of Lord Viṣṇu according to the four social divisions [brāhmaṇa, kṣatriya, vaiśya and śūdra] and the four spiritual divisions [brahmacārī, gṛhastha, vānaprastha and sannyāsa], one’s life becomes perfect.
http://www.vedabase.com/en/sb/5/19
In the Sri Lankan chronicle Mahavamsa, son of Ashoka (Mahindra) is reported to have introduced himself as an inhabitant of Jambudvipa to the Lankan king.
https://archive.org/stream/mahavamsaorgreat00mahciala#page/90/mode/2up
