About Etna Etna is a borough in Allegheny County in the U.S. state of Pennsylvania, along the Allegheny River, opposite Pittsburgh. Etna was named after the volcano Mount Etna, an allusion to blast furnaces, steel mills, galvanized-pipe works, and other manufacturers located there. Boroughs are defined, incorporated political subdivisions, but they tend to be smaller than cities. Most of the 959 boroughs in Pennsylvania, for example, have populations under 5,000, though there are exceptions. Boroughs follow a Borough Code; whereby Council is the governing body and the mayor is primarily responsible...