Habenular trigone

The habenular trigone is a small depressed triangular area situated in front of the superior colliculus and on the lateral aspect of the posterior part of the taenia thalami.

It contains a group of nerve cells termed the ganglion habenulæ.

Fibers enter it from the stalk of the pineal gland, and others, forming what is termed the habenular commissure, pass across the middle line to the corresponding ganglion of the opposite side.