Final answer:
Samara, Russia, is the city at the confluence of the Volga and Samara Rivers and is a significant location due to the Volga River's role as an important transportation network and its connection to the Caspian Sea.
Step-by-step explanation:
The city located at the confluence of the Volga and Samara Rivers is Samara, Russia. Samara is a key city in the region because of its strategic location on the Volga River, which is the longest river in Europe.
The Volga River is significant as it not only flows into the Caspian Sea, but also connects with the Don River through an extensive network of canals, linking the Caspian Sea with the Black Sea.
The importance of the Volga River as a transportation network has been recognized for centuries, facilitating trade and movement within the region.