Bhāgavata-Māhātmya and the Complete Summary of the Śrīmad-Bhāgavatam
द्वीपवर्षसमुद्राणां गिरिनद्युपवर्णनम् । ज्योतिश्चक्रस्य संस्थानं पातालनरकस्थिति: ॥ १६ ॥
dvīpa-varṣa-samudrāṇāṁ giri-nady-upavarṇanam jyotiś-cakrasya saṁsthānaṁ pātāla-naraka-sthitiḥ
《薄伽梵往世书》详述大地的诸洲、诸域、海洋、山岳与河流;亦叙说天体轮系的安置,以及地下界与诸地狱中的种种境况。
This verse states that the Bhāgavatam includes descriptions of islands/continents and oceans, mountains and rivers, the arrangement of the celestial planetary system (jyotiś-cakra), and the locations of Pātāla and Naraka.
In this chapter Śukadeva summarizes the major subject matters covered throughout the Bhāgavatam for King Parīkṣit, and cosmology (including higher and lower realms) is one of those topics.
They encourage moral responsibility and dharmic living by reminding one that actions have consequences, and they redirect the mind toward devotion and self-discipline rather than harmful choices.