Viareggio is on the line between [wiki=b8405081f19b6dcdd2388910ad898a69]Genova[/wiki] and [wiki=1f49f770adc6c84629f50ce3ca2a2109]Rome[/wiki] and can be reached by local trains from Pisa (15 minutes) and from La Spezia (1 hour). From Viareggio there is also a very slow line to Lucca (15 minutes), Montecatini (45 minutes), Pistoia (1 hour), Prato (75 minutes) and Florence (90 minutes).
The closest airport is in [wiki=322db3095458956cc0d273d05531d993]Pisa[/wiki]. From there it's possible to reach Viareggio by train (at the station Pisa Airport take the train to Pisa centrale and then the regional train to La Spezia with stops in Torre del Lago Puccini and Viareggio) or by bus (in the large square in front of the airport go to the bus stop of Vaibus and take the bus to Torre del Lago and Viareggio; tickets on board).
From [wiki=bbf5e1be3178100ef6a81c2e4ba0304e]Florence[/wiki] airport take the bus Vaibus to Lucca, Torre del Lago, Viareggio. The bus stop is in front of the airport, at the beginning of the motorway (tickets on board).
There are bus lines of Vaibus to and from Forte dei marmi, Lucca, Pisa, Florence and Montecatini.