The Carpathians River is a major river system in Central and Eastern Europe. It is composed of two main rivers, the Vistula (7 letters) and the Tisza (5 letters). The Vistula is the longest river in Poland and the second longest river in Europe, while the Tisza is the longest river in Hungary. Both rivers are important sources of water for the countries they flow through, providing irrigation, drinking water, and hydroelectric power. They also provide habitats for a variety of wildlife species.