Most of it seemed fertile, however, most will probably say the Mekong Delta. But that region is extremely wet (seemingly flooded).
because of fertile region
the praries
Western Australia
Answer to region contains fertile valley
There is no desert near or around the capital of Australia. Canberra lies in a fertile region, the rich grazing and croplands of the Limestone Plains.
This is known as the outback. It comprises vast plains of fertile land, semi-arid and less productive land, and desert.
north central
The Amazon Rainforest has some of the most fertile soil in Brazil. In addition, it has the most mineral resources.
The region known as the "Fertile Crescent," located in the Middle East, is often considered to have some of the most fertile soil in the world due to its rich sediment deposits from the Tigris and Euphrates rivers. Other regions with highly fertile soil include the Great Plains in the United States and the Pampas in Argentina.
The Midwest region of the United States, often referred to as the Corn Belt, has some of the most fertile soils in the country. The rich soils in this region, consisting of deep layers of glacial till and loess, are ideal for growing a variety of crops, particularly corn and soybeans. The region's fertile soils have made it a key agricultural area in the country.
The most fertile part of Egypt - see the link below.