The term area 29 refers to one of two parts of retrosplenial cortex. It is composed of granular cortex.The other is area 30, which is composed of dysgranular cortex. The two are narrow bands, which in the primate are aligned side by side in the ventral bank of the posterior cingulate gyrus with continuation in the rostral bank of the isthmus of the cingulate gyrus. The inner band of the two, area 29 is separated from the splenium of the corpus callosum by the callosal sulcus. rostrally in the human, the area is subdivided into an area 29m and area 29l. The portion in the isthmus was formerly considered a separate area 26. The equivalent structure in the macaque is the same as in the human, except that it is not subdivided into medial and lateral parts ( Vogt-2012 ). In rodents it is located on the mesial surface of the cortex of the cerebral hemisphere, dorsal and caudal to the splenium of the corpus callosum. In the rat it consists of three parts: zone a of the retrosplenial granular area, zone b of the retrosplenial granular area and zone c of the retrosplenial granular area ( Paxinos-2009b ). Some authors regard zone b and zone c as one, i.e., as zone b-c of the retrosplenial granular area ( Swanson-2004 ). In the mouse it may be subdivided ( Franklin-2008 ) or not ( Hof-2000 ).