The Amazon Region comprises all Ecuadorian territories to the east of the Andes Mountain Range. The mighty rivers that characterize this region have their origin in the Andes and the Amazon Mountain Range. The latter is formed by small mountain ranges that run parallel to the Andes. The rivers formed from these mountain ranges acquire greater flow as they move eastward through the Amazon Plain. Ultimately, all these small rivers form the Pastaza River and the Marañón River, which merge in Brazil to form the Amazon River.The Amazon Region constitutes almost entirely a tropical rain forest characterized by an incredible variety of plants and animals. Therefore, the Ecuadorian Amazon is considered one of the most biodiverse regions in the world. Some of the most popular destinations include El Puyo, the Yasuní and Podocarpus national parks, and the Cuyabeno Faunal Production Reserve.