San Leo Fortress

Its reputation for being impregnable is perhaps more to do with its exceptional natural position atop a soaring rocky spur than its construction.

The castle is almost certainly of Lombard origin, though its present appearance, dating from around 1470, is the work of Francesco di Giorgio Martini. The north-eastern front, which defends the approach to the castle, is entirely the work of Francesco di Giorgio Martini and comprises a long wall, held at each end by two low round towers with escarpment walls, topped with corbels and machicolations.

Behind it is the fortress itself which stands on the top of a rocky pinnacle. It pre-dates Martini’s frontage and takes its architectural shape from the natural formation of the rock.

The fortress served for many years as a papal prison. He was condemned to death for heresy and sedition by the Papal Inquisition but Pope Pius IV commuted the sentence to life imprisonment, which he served out here until his death in 1795.

In addition to Cagliostro’s cell, the castle now houses a museum and art gallery.