Srimad-Bhagavatam: Canto 5 - Chapter 1 - Verse 6
Sanskrit:
सीता तु ब्रह्मसदनात्केसराचलादिगिरिशिखरेभ्योऽधोऽध: प्रस्रवन्ती गन्धमादनमूर्धसु पतित्वान्तरेण भद्राश्ववर्षं प्राच्यां दिशि क्षारसमुद्रमभिप्रविशति ॥ ६ ॥
ITRANS:
sītā tu brahma-sadanāt kesarācalādi-giri-śikharebhyo ’dho ’dhaḥ prasravantī gandhamādana-mūrdhasu patitvāntareṇa bhadrāśva-varṣaṁ prācyāṁ diśi kṣāra-samudram abhipraviśati.
Translation:
The branch of the Ganges known as the Sītā flows through Brahmapurī atop Mount Meru, and from there it runs down to the nearby peaks of the Kesarācala Mountains, which stand almost as high as Mount Meru itself. These mountains are like a bunch of filaments around Mount Meru. From the Kesarācala Mountains, the Ganges falls to the peak of Gandhamādana Mountain and then flows into the land of Bhadrāśva-varṣa. Finally it reaches the ocean of salt water in the west.