We have already seen how Veda clearly establishes that the extent of Bharata Varsha was from the China Sea in the east to the Mediterranean and the Red Sea in the west.
Now let's look at what Purana and Surya Siddhanta have to say about this.
As per Padma Purana and Matsya Purana, the earth, the globe is of the shape of a lotus. Look at it as a lotus bud, not a blossomed lotus.
तच्च पद्मं पुराभूतं पृथिवीरूपमुत्तमम्
नारायणसमुद्भूतं प्रवदन्ति महर्षयः
It is this lotus on which creator Brahma sits, which comes out of the navel of Srimannarayana.
Now, Purana says there are four leaves attached to this lotus.
If you flatten out the globe and make it into a map that is two-dimensional, then these four leaves would appear on its surface, covering the entire surface.
Take the entire surface area as a circle and divide it into four equal sectors: one in the east, one in the south, one in the west, and one in the north.
As per Puranic geography, the sector to the south is Bharata Varsha, the sector to the west is Ketumala Varsha, the sector to the north is Kuru Varsha, and the sector to the east is Bhadrashwa Varsha, each with an extent of ninety degrees.
Markandeya Purana also says the same thing:
तदेतत्पार्थिवं पद्मं चतुष्पन्नं मयोदितम्
भद्राश्वभारताद्यानि पत्राण्यस्य चतुर्द्दिशम्

Even Brahma purana -
भारताः केतुमालश्च भद्राश्वाः कुरवस्थथा
पत्राणि लोकपद्मस्य मर्य्यादा शैलबाह्यतः
Purana says that the boundaries of these four regions are mountains, not the sea.
Surya Siddhanta says:
भूवृत्तपादे पूर्वस्यां यमकोटीति विश्रुता ।
भद्राश्ववर्षे नगरी स्वर्णप्राकारतोरणा ।। १२.३८ ।।
याम्यायां भारते वर्षे लङ्का तद्वन्महापुरी ।
पश्चिमे केतुमालाख्ये रोमकाख्या प्रकीर्तिता ।। १२.३९ ।।
उदक्सिद्धपुरी नाम कुरुवर्षे प्रकीर्तिता ।
तस्यां सिद्धा महात्मानो निवसन्ति गतव्यथाः ।
same division into four sectors.
In Bharata Varsha the most important place is Lanka.
In Ketumala Varsha on the west, Romaka.
In Kuruvarsha on the north, Siddhapuri, and in Bhadrashwa Varsha on the east, Yamakoti.
So each sector is of a span of ninety degrees.
The meridian , the longitudinal line passing through Ujjain is the exact center of Bharata Varsha.
Ujjain time used to be the standard time for us before Greenwich got recognized as the Prime meridian in 1884.
Right on this line, on the north is the Pamir mountains or the Sumeru.
Right on this line to the south in Ravana's Lanka.
Not Sri Lanka, Ravana's lanka.
Now you take 45 degrees to the east of this meridian.
121 degrees meridian east which is Taiwan.
To the west, 76 minus 45, 31st meridian to the east of Greenwich which passes through Turkey, Egypt.
Same as how Veda describes.
They are complementing each other you see.
Don't go for the exact longitude.
Borders of countries have kept on changing throughout world history.
You can see that the regions marked are the same, both in the Veda and Purana, even in Surya Siddhanta.

Knowledge Bank

Who is Agastya’s son?

Idhmavaha ( इध्मवाहः) also called Dridhasyu (दृढस्युः).

When were Vedas revealed?

Vedas are revealed at the beginning of each Kalpa. One Kalpa is 4.2 billion years and it is the lifetime of the universe. The Vedas were revealed nearly 1.97 billion years ago.