Also called the calcarine fissure, the calcarine sulcus is located on the medial surface of both occipital lobes, dividing the primary visual cortex into upper and lower portions, namely, the cuneus and the lingual gyrus, respectively. Deriving its name from the Latin word calcar meaning “spur,” it travels a slightly curved path stretching anteriorly to the parieto-occipital fissure and posteriorly to the occipital pole. Its blood supply comes from a branch of the posterior cerebral artery called the calcarine artery.