Not too far from Viareggio it is possible to visit the Cinque Terre.
Known all over the world for their beauty it is possible to reach them by boat or by train. The boat leaves the port of Viareggio every morning at 9 o'clock and comes back at 6:30 pm (service available until the 9th of September). During the tour the boat will stop for 1 hour in Portovenere and for 2 hours ad a half in Monterosso.
Otherwise you can take the train at the central station of Viareggio to La Spezia, when here you can change to another train.
It's also a wonderfull experience walk from one village to others villages.