Cosmopoli — "city of Cosimo" — is the name Cosimo I de' Medici gave to the new fortified town he founded here in 1548. The plan is still legible: a single main artery, the Salita Napoleone, climbs from the harbour up between the two forts, with a regular grid of cross-lanes branching off. The houses are simple but well-proportioned, painted in faded ochres and pinks, and the steep gradient means that most lanes are stepped rather than ramped.
The heart of the old town is the Piazza della Repubblica, just back from the waterfront — a long, narrow square framed by cafés, with a small fountain at one end and the church of the Misericordia at the other. The church contains a death mask of Napoleon and a small museum of his belongings, including a fragment of his uniform. Above the square, the lanes climb to the Chiesa di San Cristino and on to the gates of the two forts.
The old town is small enough to walk in an hour. It is at its best in the early morning before the cruise-ship day-trippers arrive, and again in the late evening when the cafés on the harbour set out their tables and the swallows hunt over the rooftops.