The mystery of the Pantheon

Mystery has always surrounded what lies behind the unusual design of the Pantheon, a great temple in the heart of Rome built by Emperor Hadrian.
Now experts have developed an intriguing theory that the temple acted like a colossal sundial, with a beam of light illuminating its enormous entrance at the precise moment the emperor entered the building.
Completed in 128 A.D., the hemispherical dome of the Pantheon is pierced by a 9-metre circular hole known as an ‘oculus’. It provides the only source of natural light inside the building.
It seems, in fact, that just at noon during the March equinox, a circular beam of light shines through the oculus and illuminates the imposing entrance to the Pantheon. ☀️