Angelina Jolie sex scene from "Taking Lives" by pablonoriegaisback
It is the bean-shaped, spongy tissue of the paraurethral gland, which is analogous to the male prostate. The actual area is only about the size of a quarter, but it feels rougher to the touch than the surrounding tissue. Because the G-spot is composed of erectile tissue, it swells up when blood rushes to it -- especially if you learn how to master the woman's G-spot effectively.
It is located about one to two inches back from the vaginal opening inside the front vaginal wall. The "front" wall is the wall of the vagina on the same side as her belly button.