Mahón (mäōnˈ) [key], Catalan Maó, town (1990 pop. 24,383), capital and chief town of Minorca island, Baleares prov., Spain, in the W Mediterranean Sea. A port with an excellent natural harbor defended by two fortresses, it is also an important air and naval base. Mahón was named for the Carthaginian general Mago. It shared the history of Minorca.