Rome's Pantheon may have been built as a massive sundial researchers reveal
It is one of the best preserved buildings from the Roman world, a 2,000-year-old testament to the immense power and wealth of the empire.
But mystery has always surrounded what lies behind the unusual design of the Pantheon, a giant temple in the heart of Rome that was built by the Emperor Hadrian.
Now experts have come up with an intriguing theory – that the temple acted as a colossal sun dial, with a beam of light illuminating its enormous entrance at the precise moment that the emperor entered the building.
Constructed on Hadrian's orders and completed in AD128, the Pantheon's hemispherical dome is punctured by a 30ft-wide circular hole known as the 'oculus'.
It provides the interior of the building with its only source of natural light and allows in rain and – on rare occasions – snow....