Iliac crest

The iliac crest is a long curved ridge along the superior border of the ilia, the large, blade-like bones of the pelvis. The iliac crest forms the prominence of the hip.

The ilia are important for bone grafts because they are large and easy to access. The ilia are also commonly used for bone marrow donation in diseases such as leukemia.

Reference: http://www.innerbody.com/image_skelfov/skel18_new.html