The largest rainforest and river system on Earth — flat, wet, and overwhelmingly forested. Abundant resources but difficult soils, unpredictable flooding, and dense vegetation restrict large centralized states. Instead, civilizations develop along river networks as small, dispersed, boat-based societies with deep ecological specialization. Geography makes mobility aquatic, settlement linear, and cultural zones highly diverse. The Amazon is a continental world unto itself, but not one that produces empire.
