The Rio Grande, known as the Río Bravo in Mexico, is one of North America's most significant rivers, extending approximately 1,900 miles (3,060 kilometers) from its source in the Rocky Mountains of Colorado to its mouth at the Gulf of Mexico. It serves as a vital water source for millions and forms a natural border between the United States and Mexico, particularly between Texas and several Mexican states including Chihuahua and Coahuila.

The River Rhône is one of the major rivers of Europe. It rises in the Swiss Alps, passes through Lake Geneva and then runs through south eastern France. At Arles, near its mouth on the Mediterranean Sea, the river divides into two branches, known as the Grand Rhône and the Petit Rhône. The resulting delta constitutes the Camargue region.

The Tagus is the longest river in the Iberian Peninsula. The river rises in the Montes Universales between Cuenca and Teruel, in mid-eastern Spain, flows 1,007 km (626 mi), generally westward, and empties into the Atlantic Ocean in Lisbon, right at the point where Portuguese caravels set sail on their many voyages of discovery hundreds of years ago.

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.