Syracuse ( SIRR-ə-kewz, SERR-, -⁠kewss) is a city in New York, United States and the county seat of Onondaga County. With a population of 148,620 and a metropolitan area of 662,057, it is the fifth-most populated city and 13th-most populated municipality in the state of New York. Formally established in 1820, Syracuse was named after the classical Greek city Syracuse (Siracusa in Italian), a city on the eastern coast of the Italian island of Sicily, for its similar natural features. Surrounding brine springs made the city a major producer of commercial salt into the late 19th century, earning the nickname "The Salt City"; it subsequently became a major industrial center until the mid-20th century, and has since become a hub for higher education, research, and services. Syracuse has historically functioned as a major crossroads in the state, first between the Erie Canal and its branches, then of the New York Central Railroad network established in the mid 19th century. Today, the city is at the intersection of Interstates 81 and 90, and its airport is the largest in Central New York, a five-county region of over one million inhabitants. Syracuse is the economic and educational hub of Central New York. It hosts a number of convention sites, including a large downtown convention complex, and is home to prominent institutions such as Syracuse University, SUNY Upstate Medical University, SUNY ESF, Le Moyne College and Onondaga Community College.