Some time ago, I had the opportunity to visit Rome. I had been there a few times before, but those visits were tied to the rushed schedules of business trips, leaving me with only fragmented memories—so faint that I cannot even recall how many times I had been. Even so, during those brief stays, I remember being struck by how fragments of ancient architecture appeared throughout the city, or how the walls of the Vatican would suddenly emerge. Rome seemed to be shaped by the very history it had lived through, and moving through it felt almost like experiencing a part of human history itself.
The ruins scattered across the city no longer felt like architecture in the conventional sense. They existed instead with the presence of something closer to massive rock formations—untouchable, as if they were part of an immutable terrain. Despite encountering them only in passing, I remember feeling unsettled by the way architecture could exist as an unwavering part of the city. At the same time, although Rome is a highly artificial place, there was a sense of openness, as if one were within a vast natural environment.
The purpose of this visit was to see the Pantheon. It was a building I had long wanted to experience since my student days. I wanted to encounter, firsthand, the fundamental relationship between architecture and nature suggested by the oculus I had seen so often in photographs. And from a previous visit, I remembered its quiet, almost indifferent exterior—yet one that left a strangely powerful impression on me.
Buildings, landscapes, and terrains that have endured far beyond the span of a human life have always been deeply suggestive to me. In that sense, my interest in old architecture and cities may come from a desire to understand why certain buildings have survived—why they have not been filtered out by time. At the same time, I have always wanted to witness the conditions that allow such architecture to exist: the natural and social environments that surround it, and the delicate balance of factors that sustain such a rare and almost miraculous state.
The Pantheon, as is well documented, was constructed approximately 1,900 years ago during the reign of Emperor Hadrian—as a temple, at a time when Himiko is said to have lived in Japan. About 500 years later, it was converted into a Christian church, and it continues to function as such today. The architecture itself is remarkably simple: a rotunda approximately 43 meters in diameter, topped by a dome with a 9-meter-wide opening at its apex.
The structure is made entirely of what is known as Roman concrete—a mixture of volcanic ash, lime, volcanic rock, and seawater. The walls are about 6 meters thick at the base and taper to 1.5 meters at the top. Various techniques were employed to reduce weight, such as adjusting the composition of the concrete depending on location and introducing voids within the walls. These strategies serve structural rationality, yet at the same time appear as though they were designed purely for aesthetic effect. The seamless integration of logic and ornament, without excess, is astonishing.
That such a sophisticated understanding of materials and construction existed 1,900 years ago is remarkable. By using AI to read the Latin inscriptions carved into the stone throughout the building, I was able to glimpse how the Pantheon has served different roles across different eras. It felt as though the building itself had been entrusted with messages from the past.
Passing through a narrow, quiet street, the building suddenly appears in a large open piazza. In contrast to its calm and unassuming presence, the surrounding space was filled with tourists. Walking through the portico and passing the massive doors, I encountered the light that I had seen so many times in photographs.
It felt as though the building had given form to the act of creation described in Genesis. Beneath the light, people gathered, filling the space with activity. The air seemed to drift gently upward, and sound reverberated throughout the circular rotunda, as if the space itself were an instrument generating ambient sound.
The light changes constantly, and it felt as though the exterior had been brought inside. The sunlight, passing through the 9-meter opening, creates another “outside” within the 43-meter rotunda, asserting its presence. What had previously been taken for granted—the presence of light—became newly perceptible once it was framed by architecture. One becomes aware that the light originates from the sun.
Perhaps, like me, many visitors come to rediscover that the light they see has traveled across space—from the sun, through the vastness of the universe, to the surface of the earth. Curious about this journey, I took out my phone and searched for it. The light generated by nuclear fusion within the sun takes 8 minutes and 19 seconds to travel approximately 150 million kilometers before reaching us.
Wanting to experience this more directly, I set a timer for 8 minutes and 19 seconds. As I waited, I tried to imagine the space the light had traversed. The distance was so far beyond everyday experience that it was impossible to grasp. So instead, I relied on the scale of my own journey—14 and a half hours by plane, covering 9,500 kilometers. In my mind, I spun a globe seven and a half times per second, trying to approximate the unimaginable distance. In doing so, I felt, in some small way, the presence of light that had traveled through space.
At some point, I noticed that the position of the light within the rotunda had shifted. Though it is something we experience every day, I realized that, in that time, the earth itself had rotated.
The Pantheon is a real place, filled with a powerful and tangible light. At the same time, it is also a place that evokes the invisible—prompting one to imagine both the interior of the sun and the vastness of space. It is a building in which one feels both present and absent.
It was entirely different from what I had imagined. And yet, I could feel that a building created nearly two millennia ago continues to speak vividly to us today. I sensed that I had experienced a fragment of what architecture can be.
At the same time, I also felt how vast architecture is as a form of human intelligence—and how little of it I truly understand.
A building that does not age.
A place that seems both real and unreal.
A structure that evokes a transcendent sense of time and space.
I had come to the Pantheon to understand architecture through it. Instead, I left realizing that I understand almost nothing about architecture at all.
It was a rare and valuable day in Rome.
(Published in Hitotsuchi, “On Tile Architecture,” June 2024)