In
Greek mythology,
Sidero (, "the Iron One") was the second wife of
Salmoneus and stepmother of
Tyro. Sidero mistreated Tyro. When
Pelias and
Neleus, Tyro's twin sons, reached adulthood they sought revenge. Although Sidero fled from them into
Hera's district, Pelias nevertheless murdered her atop the altar to Hera.