Arethusa was a Nereid, a water-nymph. She was beloved by the river god Alpheus, after she had bathed in his waters, but she scorned his advances, desiring instead to remain chaste and continue to follow the goddess Artemis. Alpheus gave chase and eventually Arethusa begged Artemis to transform her so that she could escape from him. The goddess consented and transformed her into a stream, which flowed down into the earth and reemerged as a fountain on the island of Ortygia in Sicily. Her story was told by a number of ancient authors, most notably Ovid in his Metamorphoses, 5.710.