Final answer:
The Lempa River and the Cerron Grande Dam are located in El Salvador, where the river serves important functions for power, flood control, and irrigation.
Step-by-step explanation:
The Lempa River and the Cerron Grande Dam are both found in the country of El Salvador. The Lempa River is the longest river in El Salvador and the Cerron Grande Dam, also known as the 14 de Marzo Hydroelectric Dam, is a significant structure on this river, providing hydroelectric power as well as flood control and irrigation benefits. Unlike the other prominent geographical features such as the Guiana Highlands with the Angel Falls in Venezuela, Lake Maracaibo of Venezuela, and the Three Gorges Dam on the Yangtze River in China, which are located in different countries, the Lempa River and Cerron Grande Dam are specifically in El Salvador and play a critical role in the nation's infrastructure.