According to itypeusa, Ecuador is an Andean country par excellence, although the strictly mountainous area, locally called the Sierra, has an extension of just over a quarter of the total land area. In fact, Ecuador includes three distinct regions for morphological as well as environmental conditions: to the west, facing the Pacific, is the coast, in the middle the Sierra, to the east, towards the Amazon basin, the East. La Costa, extended for approx. 67,000 km², largely corresponds to an alluvial plain, largely covered with volcanic material; at most 150 km wide, it is deeply depressed near the Andean side, but rises towards the coast, on which there are isolated hills or short mountain ridges of calcareous nature (Manabí, Colonche mountain ranges etc.), generally high about 800 me formed during the last corrugations that affected the Andean region. These reliefs leave a sometimes small space to the coastal selvedge, low and articulated (bays of Manta, Santa Elena, Gulf of Guayaquil, etc.), in which some rivers have deeply affected their estuaries, while others stagnate giving rise to marshy areas. The islands bordering the Ecuadorian coast are scarce and of modest extension, with the exception of the island of Puná, located in the Gulf of Guayaquil and formed by recent eustatic movements. The richest and most populated part of the coast is the basin of the Guayas river (a term that is actually quite improper, as Guayas is the common mouth of some waterways, including the Daule and the Vinces), whose soils very fertile allow for plantation agriculture and which is home to the largest city in Ecuador., Guayaquil. The central section of the country, the Sierra (approx. 63,000 km²), is a strip of highlands over 600 km long from N to S and 100-150 km wide; it is divided into two roughly parallel Andean chains, the Cordillera Occidental and the Cordillera Oriental or Real, between which there is a depression area, an average of 2500 meters high.
The two mountain alignments, made up of strongly folded Paleozoic and Mesozoic rocks (the oldest is the Cordillera Oriental, essentially formed by crystalline rocks covered with sedimentary materials), originated from two successive Cenozoic corrugations; powerful lava layers, attesting to intense volcanic activity, cover the reliefs in several points, especially in the northern section of the Sierra. Grandiose volcanic systems, many of which are still active, overlook the two chains; in the Cordillera Oriental, morphologically more compact and as a whole higher than the Western, the Cayambe (5790 m), the Antisana (5704 m), the Cotopaxi (5897 m) and the Sangay (5230 m, one of the most active volcanoes in the world), while the Cordillera Occidental, largely fragmented by numerous river furrows, although generally presenting volcanic systems of lesser importance (Cotacachi, 4937 m; Pichincha, 4783 m), includes the mighty Chimborazo, the highest elevation in the country (6310 m). In addition to intense volcanic activity, Ecuador is affected by frequent seismic phenomena, which denounce the structural instability of the territory. Volcanic soils also covering the pit tectonic plant and that the lava flows have compartmentalized in several distinct reservoirs from each other, the hoyas (basins of Ibarra, Quito, Latacunga, Riobamba, etc.), Where the climate is particularly suitable to human settlement and whose very fertile soils have determined, since ancient times, a dense population and the location of very important centers as well as the capital itself. AE of the Cordillera Oriental extends the East, the largest (over 130,000 km²) morphological region of the country; covered by a dense forest mantle, due to its difficult access – it can only be reached by crossing the wild gorges of the few rivers that have opened a passage in the Cordillera Oriental – it is still virtually unknown in many areas and is almost entirely depopulated. Formed by a foothill area and a wide plain, the East is covered by sedimentary soils from the Cenozoic and Neozoic; they are largely alluvial deposits, which slope from W to E towards the Amazon basin. About a thousand kilometers off the coast, on an area of 8010 km² is the archipelago of Colón or the Galápagos, formed by a group of small islands, 13 of which are larger, of a volcanic nature.
Ecuador has a dense hydrographic network, which pays tribute to the Pacific Ocean and the Amazon River; the rivers, very rich in water, originate from the Andean chains and generally have a rain-nival regime. Given the greater proximity of the western reliefs to the coast, the rivers that flow down to the ocean are generally shorter; the main ones are the Esmeraldas, which is formed from the confluence of various rivers, including the Guaillabamba, and flows into the Pacific with a deep estuary where the homonymous city is located, and the aforementioned Guayas. The Amazonian rivers are especially rich in water, due to the abundant rainfall; among them of particular importance are the Napo, the Pastaza and the Tigre.