The ‘Rocca’ fortress is the largest military construction on Monte Argentario, a structure whose irregular shape allows it to mesh perfectly with the surrounding hills. Its total area spans 26,000 square meters, 14,500 of which are part of its stately walls. Nearby, you’ll find the Santa Caterina Fortress at the bottom of Monte Filippo, a structure almost leaning towards the sea. This building was also used as a hospital; it is said that renowned painter Caravaggio stayed here after being found in terrible conditions on Cala Galera beach. Like other fortresses, a sturdy wall and a drawbridge strengthen the structure.
The most important fortress in the area is Forte Filippo. The rectangular building vaunts four unequal sides and asymmetrical triangular bastions, plus a wide moat. Located on Monte Filippo, the fortress lies between the Gulf of Porto Ercole and Cala Galera beach. The only watchtower located farther from the coast is Argentiera tower, a structure built by Sienese forces in the 15th century. This stately structure is located between the valleys of Pozzarello, Forconata, Castagno and Campone.