Very beautiful castle. Not in perfect state as Chambord, but still very amazing. Cant miss it since it is the biggest attraction in town. The castle has been occupied by several famous people, such as Queen Anne de Bretagne's Father. (NB: Queen Anne de Bretagne was the last queen of Britanny).
Clisson is located 20 kilometers south of Nantes. Many trains go there everyday, some taking 20 minutes, others 30 minutes. As usual since there is only one railway company, go to www.sncf.com or at the railway station to buy tickets. Price for a go and return is around 8€.