Guaymas is a city in Guaymas Municipality, in the southwest part of the state of Sonora, in northwestern Mexico. The city is 134 kilometres south of the state capital of Hermosillo, and 389 kilometres from the U.S. border. The municipality's formal name is Guaymas de Zaragoza and the city's formal name is the Heroica Ciudad de Guaymas. The city proper is mostly an industrial port and is the principal port for the state of Sonora.