Fly either to Pisa or Florence airport
-cheap flights available to Pisa with Ryan air or Easyjet, car hire available with Hertz.
if you come by car , drive towards Siena along the motorway from Florence . take the exit of Poggibonsi north . Follow the directions to Poggibonsi centre and after 400 metres turn left towards Gavignano ( a tiny hamlet) drive for 2 kilometres. Pass Gavignano and take the first white road on your right. Oliveta is in front of you.