Filled with cerebrospinal fluid, the chiasmatic cistern is located near the optic chiasm above the sella turcica, beneath the hypothalamus, and between the uncus of the temporal lobes. It contains part of the Sylvian fissure, optic chiasm, infundibular stalk, and cerebrovascular circle of Willis. It is continuous with the interpeduncular cistern at its posterior end. The chiasmatic cistern is often the location of herniation and intracranial hypertension. It can also fill with blood in cases of subarachnoid hemorrhage.