Rio de la Plata is a large estuary located in South America, formed by the confluence of the Paraná and Uruguay rivers. It serves as a natural border between Argentina and Uruguay and is one of the widest estuaries in the world, measuring about 220 kilometers (140 miles) across at its mouth. The estuary plays a crucial role in the region's economy, facilitating shipping and trade. The Rio de la Plata is also known for its rich biodiversity, supporting various species of fish and birds. Its waters are influenced by both freshwater from the rivers and saltwater from the Atlantic Ocean, creating a unique ecosystem. The surrounding areas are home to several cities, including Buenos Aires, the capital of Argentina, which is situated on its western shore.