This imposing building, currently known as Forte dei Borgia, has antique origins: the most ancient part of the structure dates back to Roman times and it was used to defend the western side of the town.
In the following centuries, the stronghold underwent many transformations: the most important ones were carried out during the Renaissance when Rodrigo Borgia - who became Pope with the name of Alexander VI – ruled Nepi.
He eventually donated the palace to his daughter Lucrezia. Later, the Farnese family took over the fief of Nepi and they had not only the stronghold but also the whole town significantly modified: their architect Antonio da Sangallo the Younger developed an ambitious project according to which new city walls were built and they eventually encompassed the stronghold in a larger defensive system.
After having been abandoned for many centuries, a few years ago the building underwent a long restoration process that rescued antique floors and frescoes.