The Ganges-Brahmaputra Delta (also known as the Brahmaputra Delta, the Sunderbans Delta, or the Bengal Delta) is a river delta in the Bengal region of the South Asia, consisting of Bangladesh and the Indian state of West Bengal. It is the world's largest Delta and empties into the Bay of Bengal. It is also one of the most fertile regions in the world, thus earning the nickname The Green Delta. The delta stretches from the Hooghly River on the west to the Meghna River on the east. It is approximately 354 km (220 mi) across at the Bay of Bengal. Kolkata (formerly Calcutta) and Haldia in India and Mongla and Chittagong in Bangladesh are the principal seaports of the delta.