The prostate is a walnut-sized organ which can be both a pleasure center and a place where cancer can reside. The prostate is located between the bladder and the penis in the front of the rectum. The urethra, which carries urine from the bladder through the penis, passes through the prostate's center. The nerves that control erection are attached to both sides of the prostate, as they extend to the penis. The prostate produces seminal fluid, which nourishes and "carries" sperm. Male ejaculate, or semen, is a mixture of this seminal fluid and sperm. The prostate is surrounded by sensitive nerves, which is why some men enjoy anal play. The organ is also the location where prostate cancer, one of the most common forms of the disease, shows up. So, particularly if you're a male over 40, get your prostate checked annually - it can only do you good!