The Pontifical Customs are a series of buildings located at the southern ends of the municipal territory of Capalbio, in what in the past was the border area between the Grand Duchy of Tuscany and the Church State.

In Chiarone, along the Via Aurelia, there is the Palazzo del Chiarone, an imposing building preceded by a portico that in past centuries was a customs office for transit between the two states. The current name of the complex, Palazzo Boncompagni, was given by the family who lived there after the dismantling of customs. The building is divided into almost a hundred rooms, including the papal apartment, stables and a prison.

In the countryside near the village of Pescia Fiorentina, there was another customs house that was housed in the complex of the Villa del Fontino. Once the customs functions were exhausted, the structure passed to the Boncompagni family, who also owned the Chiarone palace, which in the early twentieth century sold all these properties to the Magrini family. The building that housed the customs has been recently restored.