The postero-dorsal part of the diencephalon located above the thalamus at the point where the cerebral aqueduct joins the third ventricle. Consists of the habenular nuclei, pineal body, subcimmissural organ, posterior and habenular commissures.
The epithalamus is a dorsal posterior segment of the diencephalon (a segment in the middle of the brain also containing the hypothalamus and the thalamus) which includes the habenula, the stria medullaris and the pineal body. Its function is the connection between the limbic system to other parts of the brain.