Vaginal fornix

The fornices of the vagina (: fornix of the vagina or fornix vaginae) are the superior portions of the vagina, extending into the recesses created by the vaginal portion of cervix. The word fornix is Latin for 'arch'.

Sexuality
During sexual intercourse in the missionary position, the tip of the penis reaches the anterior fornix, while in the rear-entry position it reaches the posterior fornix.