The basilar sulcus (groove for basilar artery) is a groove in the pons, part of the brainstem.
The basilar sulcus is vertical directed and lies in the midline of the pons on its anterior (front) surface. The basilar artery runs within the basilar sulcus.
The basilar sulcus is bounded on either side by an eminence caused by the descent of the cerebrospinal fibers through the substance of the pons.
A cross section of the lower pons showing the basilar sulcus at the bottom.
This article incorporates text in the public domain from page 785 of the 20th edition of Gray's Anatomy (1918)