Set between the Tuscan-Emilian Apennine and the Tyrrhenian Sea, and between the Cerreto Pass and the plains of the Arno. The coastal belt comprises the Versilia coast between Forte dei Marmi and Viareggio, as far as Torre del Lago Puccini, and is as if protected by the natural curtain of the Apuan Alps. The basin of the River Serchio, which in its Northern part is identified with the Garfagnana, is enclosed between the Southern side of the Apennine, the slopes of the Pizzorne hills and the North face of the Apuan Alps, and is characterized by the alternation of steep terraces and hilly landscape.