If you are in Tuscany, I strongly recommend you a day trip visit to Lucca. It’s 1 hour by train from Florence and 25 minutes from Montecatini Terme.

The city centre is surrounded by walls and the city is very picturesque. If you have time, rent a car and drive through Garfagnana mountains region. There are many many small cities worthy to visit: Castiglione di Garfagnana, Fornovolasco etc.