Anatomy textbooks may need to be rewritten: the penis’s main erogenous zone isn’t where we thought it was SOPA Images Limited/Alamy The most detailed neuroanatomical study of the penis to date has found that its primary erogenous zone is the frenular delta, an area that has long been left out of anatomy textbooks and surgical training. The triangular-shaped zone is located on the ventral side, or underside, of the penis, where the head meets the shaft, and may be damaged by circumcision. “Although this may seem self-evident to anyone attuned to the sensations of their penis during sexual activity, our work scientifically validates the existence of a ventral penile anatomical region that serves as a centre of sexual sensation,” write the authors of the study, led by Alfonso Cepeda-Emiliani at the University of Santiago de Compostela in Spain.…