Hotel/resort in Tuscany for 2 nights with 2 teens?

We would be traveling from Venice to Rome via train and wanted to spend 2 nights in Tuscany at a hotel/resort. We won't be renting a car, so ideally somewhat near a train stop along the way? We're renting apartments in Venice and Rome but thought 2 nights in a nice hotel might be fun. Looking for a place that would have a pool, interesting spots nearby, little bit of relaxing?

Thanks!