Travel literature is abundant in the 14th century, and several literary works narrate a journey into the Mediterranean Sea: many are the stories of men traveling into those waters, but a few feature female protagonists. The intervention of this essay is twofold. First, on the basis of Fernand Braudel’s definition of the Mediterranean as a “sea-movement” it explores the role of the Mediterranean in The Decameron by Boccaccio and “elsewhere,” especially Boccaccio’s own Filocolo, Piero da Siena’s Bella Camilla, Le Roman de Floriant et de Florete and other stories featuring women navigating in the Mediterranean in 14th century literary works. Second, it establishes who the women traveling in those waters are by asking why they travel and whether or not they themselves chose to travel. Above all, it examines the consequences of their travels on their lives. From here we arrive at the ironic title of this essay: “Mediterranean Metamorphosis.” When we wonder to what extent women have or have not been modified by their travels in the Mediterranean (the same body of water that men were constantly crossing), that sea changes from a “sea-in-movement” to a “sea-crystallized.” Women travel, leave home and return exactly as they were when they left, possibly because theirs was mostly a journey they had not chosen to make. Thus we arrive at the second part of the title, “Traveling Penelopes”: the situation of women traveling in the Mediterranean in The Decameron and “elsewhere” encompasses an illumination of a French manuscript of Boccaccio’s De Casibus, where Penelope is seen calm and smiling, working her spindle while her suitors are behind her killing each other. Therefore, most women travel in the Mediterranean paradoxically in a dimension of total immobility; no modification from who they are at their departure is foreseen. For the Mediterranean to be a “social space” or “a place of exchange and sharing”, a woman must be disguised as a man, like Zinevra and Camilla, or, like the Christian Gostanza from Lipari (Decameron V, 4). The Mediterranean in the 14th century is a dangerous place for women who have not chosen to travel in those waters, and remains a “social space” for men only.