The Bay of Bengal is the northeastern part of the Indian Ocean. The world's largest bay, geographically it is positioned between the Indian subcontinent and the Indochinese peninsula, located below the Bengal region.

South Asia is the southern subregion of Asia, which is defined in both geographical and ethnic-cultural terms. As commonly conceptualized, the modern states of South Asia include Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka. South Asia borders East Asia to the northeast, Central Asia to the northwest, West Asia to the west and Southeast Asia to the east. Topographically, it is dominated by the Indian subcontinent and is bounded by the Indian Ocean in the south, and the Himalayas, Karakoram, and Pamir Mountains in the north.