Geography of South America world by drainage area—the Amazon River and the more southerly Paraná River. The other major river of this central lowland is the Orinoco River, which has a natural channel linking it with the Amazon. Most of this central lowland is sparsely populated because the soils are heavily leached, but in the south is the very fertile pampas of Argentina—one of the world's major food-producing regions where wheat and beef cattle are pre-eminent. The natural vegetation of the northern lowlands are either savanna in the northern "llanos" and southern "campos", or tropical rainforest throughout most of the Amazon basin. Efforts to
Geography of Vietnam referred to simply as "the Chaine."), the coastal lowlands, and the Mekong Delta in the south. Vietnam is a country of tropical lowlands, hills, and densely forested highlands, with level land covering no more than 20% of the area. The spectacular Bản Giốc Waterfall is 272 km north of Hanoi and few tourists are seen there. The Red River Delta (also known as the "Sông Hồng"), is a flat, triangular region of 15,000 square kilometers, is smaller but more intensely developed and more densely populated than the Mekong Delta. Once an inlet of the Gulf of Tonkin, it has been