Inferior view of the medial temporal lobe and diencephalon. The parahippocampal gyrus has been dissected to reveal the structures of the hippocampal formation: the intralimbic gyrus, Band of Giacomini, dentate gyrus, and the uncus. The crural cistern separates the crus cerebri of the midbrain from the hippocampal formation. Posterior and medial to the hippocampal formation is the inferior surface of the thalamus, which has several prominences. The medial geniculate nucleus lies medially, the lateral geniculate nucleus is lateral, and the pulvinar is the largest nucleus of the thalamus and is present on the posterior part of the inferior surface. The ambient cistern separates the midbrain from the inferior surface of the thalamus and the posterior parahippocampal gyrus. (Image courtesy of AL Rhoton, Jr.)