This is a very popular tour of Tuscany, especially if you are spending time in Florence and don't want to drive or deal with public transportation. It is a full day, including lunch. You see a lot, and also have the option to climb the Tower of Pisa:

"Meet your local guide before heading for the hills on a scenic drive through Monteriggioni. Your first stop for the day is gothic Siena, famous for its medieval streets. Choose to join a guided tour through the city(free entry inside the Cathedral is included). Or, alternatively, you're free to marvel the sights of Siena at your own pace, enjoy a drink in an open air cafe and meet the locals.

Enjoy an escorted stroll among Chianti vineyards, olive groves and wine cellars before indulging in a traditional Tuscan lunch amongst the Sienese hills where Chianti wine is produced. Surrounded by grapes vines you'll have the opportunity to meet fellow travelers while feasting on local foods including cold meats, salads, pasta and bread. A wine-tasting class will be held during lunch including free samples of wine, honey and olive oil (which are also available for purchase).

After lunch you will visit San Gimignano where you can roam the maze of cobbled streets and small squares, grab a gelato and walk between San Gimignano's famous 14 towers. Your final stop is Pisa, where you can take an up-close inspection of The Leaning Tower, view the Cathedral, the Baptistery and monumental Cemetery in Pisa before venturing back to Florence where your full-day tour concludes.

Want to skip the long lines at the Leaning Tower of Pisa?
Upgrade to the Tour & Leaning Tower of Pisa option and you'll receive pre-booked entrance tickets. Go to the front of the queue at the Leaning Tower of Pisa without having to wait in line and experience a once in a lifetime opportunity to climb the world's most titled tower. Leaning Tower of Pisa has 296 steps over 7 floors. The climb will take approximately 30-minutes."