The nation is largely a delta, formed by silt deposited over 250 million years by two great Himalayan rivers, the Ganga and the Brahmaputra.

• 孟加拉的大部份土地，是由恒河和雅鲁藏布江这两条来自喜马拉雅山的大河夹带的泥沙，经过2亿5000万年沉积而形成的三角洲；