The upper part of the vagina leads to the external cervix, which is the entrance to the cervix. The upper segment of the vaginal forms a vaginal vault by being enclosed within the vaginal portion of the cervix. The cervix extends into the vagina, the narrow space between the cervix and the wall of the vagina is the fornix. The recess between the posterior lip of the cervix and the wall of the vagina is the posterior fornix and it is the deepest and a common site for ruptures, foreign bodies, and malignancies.