This river, winding through the jungle, belongs to the Orinoco system. The river and its tributaries are the northernmost of South America’s four principal river systems. From its source in the Parima Mountains of the Guiana Highlands, the snow-fed waterway flows through the grasslands of the llanos and across dense rainforest before reaching the Atlantic Ocean. The Orinoco’s waters carry a tremendous load of sediment that is deposited at its mouth, forming a vast delta with many distributaries.