The Mystery of the Pantheon

The Pantheon is the most spectacular ancient building in Rome and the eternal favorite of this writer. On a recent trip to Rome I was amazed by the shaft of light shining through the oculus (eye) in the roof which illuminated the circular dome, walls and floor. On dozens of visits in the past to the site this phenomenon has never revealed itself to me, and yet it was very likely the intention of those who designed it 2,000 years ago. In essence, the oculus functions as a grand sundial, by which the ancients could not only count the hours of the day, but also the passage of the seasons. To see it yourself, aim for mid-afternoon on a clear day, when the sun is brightest in the sky.