The Iliacus is a paired smooth muscle located on the anterior surface of the pelvis, below the celiac border line. It originates from the sacrospinous ligament and passes downward to meet the internal genital ridge. It then passes into the hip joint, where it connects to the acetabulum. The largest portion of the muscle is found in the pelvic canal and pelvic cavity (also known as the inguinal fossa). Its length is about 15 cm and its thickness is about 2 cm.