The oldest building in Rome that has remained intact. Called the Temple of All the Gods, it was built in the first century CE and is an architectural marvel that has inspired many architects. Its uniqueness lies in the oculus (the eye), the central opening in the dome of the building, through which smoke rose as a sacrifice to the gods, and from which light and rain enter. It is recommended to look from outside at the special shape of the walls that enabled the successful construction of the dome, 43 meters in diameter, without supporting columns. Today, the Pantheon is a church dedicated to all the martyrs, and some of Italy’s kings and the great painter Raphael are buried there.