Iliac crest forms the margin of ilium, and is a curved and broad structure that helps protect the inside of pelvic region. This crest forms the curved superior border area of the Ilium. Ilium is the largest of the bones that merge together to form the hipbone. There are usually three bones that merge and form the hipbone. Iliac crest is located on lateral edge of the superior of the Ilium and it is very close to the surface of skin within the hip region.