Casa del sole, Pescia, is located off the autostrada, in between Pisa and Florence, just 40 minutes drive from Pisa, Florence, Abetone (skiing), the Garfagnana (national park) and the seaside. Siena is only 1 ½ hrs drive. Have a look at the maps section.
There are countless areas of interest within easy reach ranging from rural walks to top night spots. In Summer you can soak up the sun and in winter you can take a trip to the mountains for some skiing.
The village of Collodi, the birthplace of the author of Pinocchio, is very close and has a lovely park dedicated to the writer.
The owners can give you many ideas for trips depending on your requirements.
Lucca:
A beautiful medieval walled city within 20 mins drive of the farm.
A real gem of a town with lots of historic sites and even more smart shops. Plenty of free parking outside the walls
Not to miss:
Hire a bike and cycle around the spectacular walls.
Go shopping!
Spend Sunday evening in Lucca - it's the traditional night for getting dressed up and having a wander. Make sure you try one of the fabulous restaurants - there are plenty to choose from. Lucca hosts a large Music festival in July. There are always a wide range of international stars who play to a tiny audience capacity of 4,000. The tickets aren't usually expensive and are available in Pescia.
Florence:
Doesn't need much of an introduction! 40 mins from Casa del Sole on the train or in the car.
Parking is difficult so take one of the regular trains from Pescia into the heart of the city.
Not to Miss:
Apart from all the museums, galleries and general culture, don't miss Ponte Vecchio - structurally amazing and full of jewelery shops!
The Duomo is stunning and worth a queue.
Siena:
Famous city 1.5 hours drive from the farm.
Not to Miss
Visit the Duomo - it's interior is really impressive.
The Campo where the horse racing takes place is a phenomenon.
Lots of loveley shops.
On your way home visit San Gimengano - really beautiful hill town.
Sea-side: 
Viareggio is 40 minutes away by car from Casa del Sole
Not to Miss
Italian beaches are very different affairs to those in the UK - hire a lounger from one of the bars along the front and soak up the sun and the atmosphere.
Walk along the main boulevard and do some more shoping.
Go to the far end of the beach and ogle the big boats in the harbour.
Abetone / Skiing:
The Italian ski resort of Abetone is 1.5 hours drive from the farm. There is decent snow from December to April.
Not to Miss
Ski! It's really cheap to hire equipment and daily passes are very reasonable.
Have a lesson - they are great fun. Most instructors speak English.
During summer the ski lifts operate to take walkers high into the mountains - enjoy the view or go for a hike.