Set in the Maremma plain, the small town of Campagnatico belonged to the Aldobrandeschi family until 973 and since the second half of the XIII century, when it was conquered by Siena.
Framed by a wonderful landscape of vineyards and olive groves, the military architectures of Campagnatico are still visible, such as the city walls, built between the XII and the XIII century, the remains of the Aldobrandeschi fortress, the castle of Montorsaio, documented since the VIII century, the castle of Sertignano, owned by the Aldobrandeschi family until 1274 and the remains of the castle of Monte Leoni.
The Church of San Giovanni Battista, realised in Romanesque-Gothic style in the XIII century, is located in one of the higest point of the town. It has only one nave, with a small rose window and a beautiful XIII century fresco picturing "Madonna con Bambino".
The former Church of Sant'Antonio Abate, in Romanesque style, once has one of the most particular façade of the Maremma plain. Now it is a theater since 1883.
The Church of Santa Maria della Misericordia is set at the entrance of the town, on the remain of a pre-existing cell, still mentioned before the XI century. Important frescoes picturing scened of Our Lady's life and discovered in the nave of the church, are now preserved at the Church of San Giovanni Battista.