In this chapter, I analyse passages that refer to water features, such as rivers and wells, in the Hippocratic gynaecological treatises. I suggest that the Hippocratic authors drew analogies between the vessels of the female body and riverbeds, thereby pointing to a form of holism in which the female body was a microcosm of the earth, furrowed by watery channels. A young woman’s vessels were narrow and prone to blockages, but they widened and became more easy-flowing as a woman gave birth. The transition from parthenos to gynē, then, was one associated with fluidity. To understand better the context of the Hippocratic texts, I discuss ancient rituals involving water that marked a woman’s transition into adulthood. These rituals often involved the Nymphs who resided in rivers and wells.