A spot ?

The A-Spot, AFE-zone or Anterior Fornix Erogenous Zone. Also referred to as the Epicenter, this is a patch of sensitive tissue at the inner end of the vaginal tube between the cervix and the bladder, described technically as the 'female degenerated prostate'. (In other words, it is the female equivalent of the male prostate, just as the clitoris is the female equivalent of the male penis.) Direct stimulation of this spot can produce violent orgasmic contractions. Unlike the clitoris, it is not supposed to suffer from post-orgasmic over-sensitivity.