Esmeraldas is a city in Ecuador. It is the seat of the Esmeraldas Canton and the capital of the Esmeraldas Province. It has an international sea port and a small airport (IATA location identifier: ESM). Esmeraldas city is a major seaport of northwestern Ecuador. It lies on the Pacific coast at the mouth of the Esmeraldas River. The city is the chief trading centre for the region's agricultural and lumbering resources but is only slightly developed industrially. It is the terminus of the 313-mile (504-km) Trans-Ecuadorian Pipeline from the oil fields in northeastern Ecuador.