It can be found in the region of the superior part of the rhomboid fossa.

The latter end by arborizing around the cells of the medial nucleus, which is situated in the area acustica of the rhomboid fossa.

The vagal triangle overlies the dorsal vagal nucleus and is situated on the caudal end of the rhomboid fossa or 'floor' of the fourth ventricle.

In the upper part of the medulla oblongata, the hypoglossal nucleus approaches the rhomboid fossa, where it lies close to the middle line, under an eminence named the hypoglossal trigone.

In the human brain, the rhomboid fossa is divided into symmetrical halves by a median sulcus which reaches from the upper to the lower angles of the fossa and is deeper below than above.

The roof of the fourth ventricle is formed by the cerebellum (superior and inferior medullary vela), the floor by the rhomboid fossa, and the side "walls" formed by the cerebellar peduncles.

The anterior part of the fourth ventricle is named, from its shape, the rhomboid fossa, and its anterior wall, formed by the back of the pons and medulla oblongata, constitutes the floor of the fourth ventricle.

In the superior part of the rhomboid fossa, it corresponds with the lateral limit of the fossa and presents a bluish-gray area, the locus ceruleus (which owes its color to an underlying patch of deeply pigmented nerve cells, termed the substantia ferruginea).