Tuscany is not famous for its beaches, although it does have around 400 km of coastline. Some of its resorts, like Viareggio, become too crowded in the summer and don't offer much to see. However, the Maremma coastline and the island of Monte Argentario offer truly spectacular views and are worth a visit.
Generally, the beach season runs from May through September. The best time to enjoy these outstanding natural treasures is the mellow season during September and October. After the school starts prices drop significantly and you can get much more space to yourself at the beach.
Go to Porto Santo Stefano or Porto Ercole which offer some of the best beaches in the region, like Cala Gelso with its coves and crystal clear waters. You can drive through the famous “strada panoramica” which offers spectacular photo opportunities as well.