I’m Venetian, but I’ve to say: Tuscany is amazing. From every point of view.
Tourists usually visit Florence, Siena, even Lucca… but there’re tons of hidden treasures in this region. So basically my suggestion is to rent a car, as soon as the opportunity happens, and take a road through the territory: wherever it takes you, it will have been an excellent choice.
One of my favourite spot in Tuscany is San Galgano Abbey: it’s so easy to reach, so do it even if you’re super tired (I swear, the parking lot is very close to the Abbey).
Jump out of your car and you’ll find it in front of you, immersed in the yellow fields of wheat still to be harvested.
And be prepared to be stunned.
San Galgano would be a masterpiece of Gothic architecture if it were not that its roof, collapsed in ancient times, has decreed its total abandonment and its charm.
The place is truly magical: you are in an open-air cathedral, it looks like an unreal place, something lost forever. The remains of the collapsed cross vaults, the capitals, the circular window open in the square apse.: this sort of ‘skeleton’ is majestic and you can still feel the holiness of the place.
A short (and super easy) path uphill leads to the hermitage of Monte Siepi, the church where a sword (Excalibur?) is kept. The church, built in 1181, is small and engrossed, with a central plan, surmounted by a dome decorated in concentric circles of white and red bricks. A little masterpiece.