''Monte Argentario land of cliffs, enchanting beaches and princely villas, but especially of ancient and superb fortifications. Scattered here and there on the advanced points of the promontory stand the silent witness to a past era,when invasions were much more dangerous than those by present-day tourists''. 

Monte Argentario is a promontory anchored to the main land by two cables, the thin Feniglia and Giannellatombolos, which connected it only at the end of the pre-historical age. Between Feniglia and Giannella there is a third tombolo where the town of Orbetello is located. A bridge connects this town to Monte Argentario. The two main villages of the promontory are Porto Santo Stefano on the north-east side and Porto Ercole, the oldest village, on the south-east one.
Anciently inhabitated by the Phoenicians, who probably founded Porto Ercole, the Argentario was soon occupied first by the Etruscan and then by the Romans, who built the town of Cosa, on the continent, and several villas scattered on the mountain.
Under the emperor Constantine (312 A.C) the Argentario was given as a gift to the Roman Church of the Saints Peter and Marcelline.
Since 1300 the region was dominated by the Republic of Siena, but a bad administration caused an almost complete ruin.
In 1577 the Argentario passes under the Spanish domination of Philip II, who merges it into the State of the Presìdi. The region becomes then an important military center, as proved by the imponent forts built above Porto Ercole.
Apart from a short period of Austrian occupation (1714 - 1735) the Spanish domination lasted until 1801.
After a few years under French control due to the Napoleon campaigns, the Argentario was annexed to the Granducato di Toscana, and later, with the Plebiscito, unified to the Italian Kingdom.
In 1842 was established the municipality of Monte Argentario which includes the two villages of Porto Ercole and Porto Santo Stefano.