Porto Ercole is a city in the region of Tuscany. It is part of the town, Monte Argentario, in the province of Grosseto. Porto Santo Stefano (the most populous) is one of the two major towns that form Monte Argentario.
The historic core is enclosed within its walls, which were erected by Siena in the Renaissance, on pre-existing structures.
The Palace of the Rulers overlooks the picturesque Piazzetta Santa Barbara, which overlooks the harbor. The building, built in the sixteenth century, preserves the facade in Renaissance style of the past. The building housed the Spanish rulers, and at the opposite end of the square on the side that looks towards the sea, is the fifteenth bastion of Santa Barbara.
Worthy of note is the Giardino Corsini, in which there are many rare tropical and subtropical botanicals.
The country is dominated by the mighty fortress Aldobrandesca, a fortification built on several occasions between the Middle Ages and the Renaissance around existing structures.