Final answer:
The Pantheon was a dome-shaped temple built by the Romans. It had an oculus at the top to allow light in. The dome was made with unreinforced concrete, and it remains the largest of its kind.
Step-by-step explanation:
The Pantheon was a temple built by the Romans. It was dome-shaped and had a hole in the top to allow light in.
The dome of the Pantheon was made with unreinforced concrete and is the largest unreinforced concrete dome in the world.
The oculus, a round or elliptical opening at the top, served as the only source of light in the building.