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. There is an anterior fornix, a posterior fornix, and two lateral fornices. The fornices vary in shape and size, with the posterior fornix being the largest. The word is Latin for 'arch'.
During sexual intercourse in the missionary position, the tip of the penis may reach the anterior fornix, while in the rear-entry position it may reach the posterior fornix.
The anterior fornix is also called the a-spot, an analogue to the g-spot (Gräfenberg spot), which is closer to the vaginal opening, and also on the anterior side of the vagina.