Sundials - World's Oldest Clocks

North American Sundial Society

Ancient Sundials

Sundials from Egypt, Greece, Roman and beyond contribute to the rich heritage and history of gnomonics and dialing


One of the most iconic buildings in the world, the Pantheon in Rome is an enduring testament to the power and glory of ancient Rome.  At the same time, it has also always posed something of a mystery.  The only source of natural lighting is a thirty-foot diameter hole at the very top of the hemispherical dome, often referred to as the "oculus".

Working since 2009, scholars Guilio Magli and Robert Hannah discovered that at midday on the equinoxes, a shaft of circular light shines through the oculus and illuminates the Pantheon's entrance. 

Read more: Pantheon Sundial