The Iguazu River is a significant waterway in South America. The Iguazu River flows through Brazil and Argentina. It forms part of the boundary between the two countries. The river is approximately 1,320 kilometers (820 miles) long. It originates near the city of Curitiba in the Brazilian state of Paraná and flows westward, eventually joining the Paraná River.

The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from sub-atomic particles to entire galactic filaments.

The Puelo River is a stunning waterway located in the Patagonia region of South America, running through both Chile and Argentina. Known for its turquoise-blue waters, it flows through pristine valleys, snow-capped mountains, and dense forests, making it a favorite destination for nature lovers, anglers, and adventurers.

The Congo River, also known as the Zaire River, is the second-longest river in Africa, after the Nile, and the deepest river in the world, with depths reaching over 220 meters (720 feet). It is approximately 4,700 kilometers (2,920 miles). The river originates in the highlands and mountains of the East African Rift, flowing through the Congo Rainforest. It empties into the Atlantic Ocean. It covers over 4 million square kilometers, spanning multiple countries in Central Africa.

The Mekong River is one of the longest and most important rivers in Southeast Asia, flowing through six countries: China, Myanmar (Burma), Laos, Thailand, Cambodia, and Vietnam. It originates in the Tibetan Plateau of China and travels approximately 4,350 kilometers (2,703 miles) before emptying into the South China Sea.

The Danube is the second-longest river in Europe, after the Volga in Russia. It flows through Central and Southeastern Europe, from the Black Forest south into the Black Sea, the Danube is the soul of Central Europe. Once a long-standing frontier of the Roman Empire, the Danube is one of Europe’s most famous waterways.

The Rhine River is one of the longest and most important rivers in Europe. It flows approximately 1,230 kilometers (760 miles) from its source in the Swiss Alps to its mouth at the North Sea in the Netherlands. The Rhine has historically been a vital waterway for trade, cultural exchange, and strategic defense, shaping the economies and histories of the regions it traverses.

The Volga is the longest river in Europe and the longest endorheic basin river in the world. Situated in Russia, it flows through Central Russia to Southern Russia and into the Caspian Sea. Exploring the Volga River unveils not only the grandeur of Russia’s longest watercourse (3,531 km or 2,194 mi) and a catchment area of (1,360,000 km2 or 530,000 sq mi) but also the rich biodiversity that thrives in and around its waters.

The Elbe River is one of the major rivers of Central Europe. It rises in the Giant Mountains of the northern Czech Republic before traversing much of Bohemia, then Germany and flowing into the North Sea at Cuxhaven, 110 kilometres (68 miles) northwest of Hamburg. Its total length is 1,094 km (680 mi). The Elbe's major tributaries include the rivers Vltava, Saale, Havel, Mulde, Schwarze Elster, and Ohře.

The Amazon River, located in South America, is renowned for being the largest river by discharge volume of water in the world. It discharges about 215,000–230,000 cubic meters per second, which is approximately 6,591–7,570 cubic kilometers per year. This volume is more than the next seven largest independent rivers combined and accounts for about 20% of the global riverine discharge into oceans.