Pantheon

• Raphael's Tomb
• Dome
• Oculus

• The Oculus: Stand directly beneath the 8.2-meter (27-foot) opening at the dome's apex, the Pantheon's sole natural light source, and observe how a circular shaft of light illuminates the interior, shifting throughout the day.
• Raphael's Tomb: Locate the tomb of the Renaissance master Raphael on the left as you enter, marked by a bust and epitaph, and pause to appreciate the resting place of one of history's greatest artists.
• The Dome's Interior: Look up and marvel at the intricate pattern of diminishing coffers, originally adorned with gilded bronze rosettes, which not only contributed to its beauty but also reduced the dome's weight.
• Original Marble Floor: Observe the geometric patterns of the floor, a mosaic of porphyry, granite, and yellow marble, much of which dates back to Hadrian's original construction.
• niches and Altars: Explore the various niches around the rotunda, once housing statues of Roman deities, now converted into Christian altars and chapels, each with its own significant artwork.
• The Portico: Before entering the main rotunda, stand beneath the imposing colonnade of 16 monolithic Corinthian columns, marveling at their scale and the intricate carving of the pediment.

The Pantheon's history is a layered narrative. Originally built by Marcus Agrippa in 27–25 BC, this earlier structure was likely rectangular and dedicated to the twelve Olympian gods. It burned down twice before Emperor Hadrian entirely rebuilt it between 118 and 128 AD, creating the circular, domed edifice we see today. Hadrian, an emperor with a profound interest in architecture, sought to create a monument that encapsulated the cosmic, a temple dedicated to "all the gods" (Pan-theon). Its remarkable preservation is largely due to its conversion into a Christian church, Santa Maria ad Martyres, by Pope Boniface IV in 609 AD. This saved it from the fate of many other ancient Roman buildings, which were often stripped for their materials. Throughout the centuries, it continued to serve as a burial place for significant figures, including kings of Italy and prominent artists like Raphael, solidifying its enduring role in both religious and secular history.

• Visit in the late morning (around 11 AM - 1 PM) to experience the full effect of the sunbeam piercing through the oculus, especially on a bright day.
• Go during an off-peak season (winter, early spring/late autumn) or during the earliest open hours to avoid the most intense crowds, as it can get very busy.
• Look up immediately upon entering to fully appreciate the dome's colossal scale and the breathtaking oculus.
• Dress respectfully, covering shoulders and knees, as it is an active church. Security personnel may enforce a dress code, especially during peak seasons.
• Bring a wide-angle lens for photography to capture the entirety of the dome and interior space.
• Stand in the center of the rotunda to experience the perfectly spherical volume and the acoustic properties of the space most effectively.

• The Pantheon's dome is wider than the dome of St. Peter's Basilica and is the largest unsupported concrete dome in the world, a feat of engineering that remains unmatched in its era.
• Despite being open to the sky, the floor of the Pantheon doesn't typically flood: 22 ancient drainage holes in the center of the floor efficiently manage rainfall.
• The building itself was once approached by a flight of steps, but due to centuries of Rome's rising ground level, street level is now above its original base.
• The bronze roof tiles of the Pantheon were infamously stripped by Emperor Constans II in the 7th century, intending to ship them to Constantinople, but they were intercepted by Arab forces.
• The Pantheon's original pediment likely featured a massive bronze eagle, though details about its full sculptural program are debated.
• It is rumored that the original architect of Hadrian's Pantheon was Apollodorus of Damascus, who was later executed by Hadrian for criticizing his architectural drawings.