What first comes to my mind is that one or more rivers feature very prominently in these civilizations: the Nile in the Egyptian and the Tigris and Euphrates in the Babylonian.
Nepal measures about 880 kilometers (547 mi) along its Himalayan axis by 150 to 250 kilometers (93 to 155 mi) across. It has an area of 147,516 km2 (56,956 sq mi).
From my perspective the crop is called "Poppy Crops".
