Final answer:
The glabella is a slight depression found on the frontal bone of the skull, located at the midline between the eyebrows.
Step-by-step explanation:
The glabella is a slight depression located on the frontal bone, which is the single bone that forms the forehead. Specifically, the glabella is found at the anterior midline between the eyebrows. The frontal bone also contributes to the formation of the supraorbital margin of the orbit and is thickened just above this margin to form the brow ridges. Additionally, the frontal bone is involved in forming both the roof of the orbit and the floor of the anterior cranial cavity, playing a significant role in the structure of the skull.