The Pantheon, located on the Piazza della Rotonda, is the Temple to all Gods, the most well-preserved Roman ancient structure. It is universally acknowledged that it was built according to the project of the emperor Hadrian in the 1st century AC. The first erected temple of the 29 BC was created by Agrippa and had a traditional rectangular floor plan, from which only one portico remains intact. The building that tourists can marvel at today was built in 118 AC. The temple is cylindrical with a semi-spherical dome. The facade is made up of a massive portico with a pediment. The majestic dome, whose radius equals the height of temple walls, creates a sense of harmony and order. The interior of the Pantheon has a diameter of 43,4 meters and the only source of sunlight is located at the top of the dome. The temple was christened in the 7th century. Many Italian monarchs are buried there, but the main burial is the tomb of Raphael.