  Despite being one of the most recognisable buildings from ancient Rome, the
Pantheon is poorly understood. While its architecture has been well studied,
its function remains uncertain. This paper argues that both the design and the
meaning of the Pantheon are in fact dependent upon an understanding of the role
of the sun in the building, and of the apotheosised emperor in Roman thought.
Supporting evidence is drawn not only from the instruments of time in the form
of the roofed spherical sundial, but also from other Imperial monuments,
notably Nero's Domus Aurea and Augustus's complex of structures on the Campus
Martius: his Ara Pacis, the "Horologium Augusti", and his Mausoleum. Hadrian's
Mausoleum and potentially part of his Villa at Tivoli are drawn into this
argument as correlatives. Ultimately, it is proposed that sun and time were
linked architecturally into cosmological signposts for those Romans who could
read such things.
