Tuscany

I don't know about trekking, but having a car, at least for a day, in San Gimignano, would make it much easier to visit nearby towns and villages. Buses from/to Poggibonsi (the main hub in the Alta Val D'Elsa) are not that frequent. There are nearby towns that you should visit while in S.Gimignano, however they aren't really walking distance from it. For example: Certaldo (Boccaccio's birthplace)=8 miles Colle Val D'Elsa=8 miles Monteriggioni=15 miles
Volterra=15 miles There aren't too many major rental companies in San Gimignano proper (it's a small town), however I found this one. They even rent Vespas, which would be a memorable experience if you feel up to driving a two wheeler. http://www.bellinibruno.com/rental-sangimignano/whoweare.htm

There's a nice hike to the ruined 13th century village of Castelvecchio, which was abandoned due to plague. Parks of it are a bit overgrown, but when you get to the village, you can explore the ruins of a number of buildings, including a castle and a church. You start in the tiny village of San Donato, just outside of San Gimignano.

San Donato is one of my favorite little places in Italy. It has tons of photo opportunities, and the first time I stayed there I was completely enamored. The view out of my little B&B was perfect, and when we arrived in the town there was a group of women painters working on images of Tuscany. It was like a scene out of a movie!

Thank you very much for replying, your help is much appreciated I had a follow up question, how can we reach San Donato from San Gimigano? Is it a walkable distance, and would anyone have information on how to reach there? Also, does anyone have a map of the hike to Castelvecchio, or is this something we can find out from the tourist office is San Gimigano? Thank you!