Poggio Imperiale announces itself with an avenue, a long, straight, cypress-lined approach running up from Porta Romana in Florence, with statues in niches and the villa waiting at the top like the end of a sentence. It began as a Medici property in the sixteenth century, but its grand form came in the 1620s, when Maria Maddalena of Austria, wife of Cosimo II, enlarged it and gave it the name Imperiale in a nod to her Habsburg origins. The cool neoclassical front you see today was added in the early nineteenth century under Napoleonic rule.
It is still a working school, an old state boarding school for girls, so access is limited and the building sits in a different mood from the villas that are museums. That is part of its charm. You can admire the avenue and the facade from outside, and ask about visits, but do not turn up expecting a ticket office.
Florence itself is a bad place to ride in a hurry. Narrow streets, a huge restricted traffic zone with cameras, and trams make the centre hostile, but the southern edge where Poggio Imperiale sits is a good launching point for the ride toward Siena. Fuel is no problem, since the suburbs of Florence and nearby Grassina have petrol stations on every main road. The old Via Chiantigiana, the SR222, leaves the city through Grassina and climbs into Chianti, one of the loveliest rides in central Italy: rolling hills of vines and olives, stone farmhouses, cypress-lined drives and road signs for Greve and Panzano. The corners are moderate, the surface mostly fine, and the rhythm is relaxed, but weekend traffic includes cyclists, camper vans and slow tourists, so start early.
Siena, the other half of the ride title, is a medieval city built on three ridges, with a shell-shaped main square that hosts the Palio horse race twice each summer. Its centre is closed to most traffic, so park outside and walk. Between the two cities there is no shortage of wine cellars, though riders should decline the tastings politely or share the glass with a passenger. Late April, May and the weeks around the October grape harvest are the loveliest times, when the hills are green or gold and the light does the work.