My wife and I are going to Italy in August and will be driving from Rome to Florence. I think it's about a three hour drive but we'd like to take most of the day and visit some places along the way. Any recommendations for stops would be greatly appreciated.

We've got two further days in Tuscany after Florence staying west near Pisa, so for this particular day places around Siena/Chianti would be best. This will be on the 14h August, I think the day before the 2nd Palio (don't really know how to check) in Siena - will Siena likely be very crowded, and therefore one to avoid. I've been to Siena but my wife hasn't - my thoughts were that there would be equally nice places to see instead, if you know where to look.

Thanks in advance.