The Pantheon, one of the most emblematic buildings of ancient Rome, was completed around 123 AD. It stands on the circular foundations of the original temple of Agrippa, destroyed in a fire in 80 AD. The current structure, probably designed under the emperor Domitian and built during the reign of Hadrian starting from 114 AD, it has an imposing entrance (pronaos) which leads to a vast interior dominated by a dome. This dome, a marvel of ancient engineering, is naturally lit through the oculus at its peak and constructed of different types of concrete, progressively lighter towards the top to reduce pressure on the structure below. The dome rests on a massive cylindrical ring, supported by sturdy foundations. The interior of the Pantheon is an example of harmony and diversity: the floor combines circles of red and gray Egyptian granite set in squares of ancient yellow ornamental marble, surrounded by red granite on a background of white and purple Phrygian marble. The side walls are interspersed with seven exedras, some rectangular and others curved, all enriched with benches and columns. A notable detail of the Pantheon are the coffers, panels recessed into the ceiling distributed in five horizontal rows. In addition to their decorative value, these geometric elements are functional, lightening the weight of the dome. Around 1740 the architect Paolo Posi renewed the upper niches with stuccos and pediments, while some original elements, such as the marble capitals, have been lost. During the twentieth century, some parts of the structure were restored, restoring elements of the ancient attic decorative scheme. The exedras, alternating with small aedicules with triangular or curved pediments, were restored in the Renaissance, and today house Christian statues that replace the ancient representations of pagan divinities. In summary, the Pantheon not only bears witness to Roman architectural ingenuity but is also a historical palimpsest, with layers of interventions that reflect different periods and styles, from its original use as a pagan temple to its current function.