Pṛthivy-Āyāma-Vistara (Extent of the Earth) and Jambūdvīpa–Navavarṣa Description
प्रपातविषमैस्तैस्तु पर्वतैरावृतानि तु / संततानि नदीभेदैरगम्यानि परस्परम्
prapātaviṣamaistaistu parvatairāvṛtāni tu / saṃtatāni nadībhedairagamyāni parasparam
Those regions are enclosed by mountains made rugged by precipitous falls, and are continually divided by many branches of rivers; thus they are mutually inaccessible.