What river serves as a key access route in southern France?

The Rhône River is a vital artery in southern France, both geographically and economically. Flowing from the Swiss Alps into the Mediterranean Sea, it traverses a diverse landscape and connects several key cities, including Lyon, Avignon, and Marseille. It is renowned for its scenic beauty and is a popular route for both commercial navigation and tourism.

The Rhône has historically served as a major trade route, facilitating the transport of goods and people. Its basin is rich in agricultural resources and is known for vineyards producing famous wines, particularly from the regions surrounding the river. The river's importance is further enhanced by its role in connecting various infrastructures, such as highways and railways, thus supporting regional development.

In contrast, while the Loire River is the longest river in France and crucial to various regions, it primarily flows through the center and western parts, making it less significant in southern France specifically. The Seine, which flows through Paris, is more associated with northern France. The Po River is located in Italy, far removed from the context of this question. Thus, the Rhône stands out as the key access route in southern France due to its geographical significance and economic contribution.