The ecoregion is bounded on the east and northeast by montane tropical rain forests; the Mizoram-Manipur-Kachin rain forests covers the Chin Hills and Chittagong Hills to the east, extending into Myanmar and other states of Northeast India, while the Meghalaya subtropical forests covers the Garo-Khasi-Jaintia Hills of Meghalaya and southern Assam, and almost defines the Bangladesh border with Northeast India. To the north, the ecoregion extends to the base of the Himalayas, where it is bounded by the Terai-Duar savanna and grasslands. The upper portion of the Brahmaputra valley in Assam is home to the humid lowland Brahmaputra Valley semi-evergreen forests. To the northwest, the forests are bounded by the Upper Gangetic plains moist deciduous forests. The dry Chota Nagpur dry deciduous forests lie on the Chota Nagpur Plateau to the southwest. The Sundarbans freshwater swamp forests and Sundarbans mangroves ecoregions lie in the swampy, semi-brackish and brackish southern reaches of the Ganges-Brahmaputra Delta bordering the Bay of Bengal.