Temple of Hadrian

Run your hand along the air, just short of the stone. In front of you rises a row of tall marble columns, grey and cream, their surfaces pitted and chipped like old bark. Behind them stands an ordinary office facade, with windows and shutters. The square around you is small and enclosed. Footsteps echo off the paving, and café chairs scrape on the cobbles. This is Piazza di Pietra, the Square of Stone. And this wall of columns is one of the strangest sights in Rome.

What you are looking at is the surviving flank of a Roman temple. Eleven columns still stand in a single line. Each one is fluted, which means it is carved with long vertical grooves that catch the shadow. At the top, each column carries a Corinthian capital, a crown of carved acanthus leaves. Above them runs a heavy band of stone called the entablature. Much of it is worn and broken. Even so, it still holds its line across the whole square.

The temple honoured the emperor Hadrian. He ruled the Roman world in the early second century and died in the year 138. His adopted son and successor, Antoninus Pius, asked the Senate to declare Hadrian a god. The Senate agreed. Antoninus then built this temple to the new god, and it was dedicated in the year 145. Romans called it the Hadrianeum. So the building is a son's monument to his father. It also marked a transfer of power, written in marble.

Here is the first surprise. You are not standing at Roman ground level. Over nearly two thousand years, the city slowly rose. Floods brought mud, buildings collapsed, and new streets were laid on top of the old ones. Look down at the base of the columns. In front of them you can see a sunken area, several metres below your feet. That lower level is much closer to the ground the Romans walked on. The columns once rose from a high platform, and this temple towered over the street.

This was part of the Campus Martius, the Field of Mars. In early Rome it was an open plain outside the city, used for military training. By Hadrian's time it was filled with grand public buildings. A short walk west of here stands the Pantheon. Hadrian rebuilt that great domed temple during his reign. So when you stand here, you stand between two of his legacies. One is the building he made. The other is the building made for him after his death.

Now look at the wall behind the columns. Between them you can see large blocks of darker stone. These blocks belonged to the inner chamber of the temple, called the cella. The cella held the cult statue, and only priests and officials went inside. The columns you see today ran along one long side of that chamber. A matching row once stood on the opposite side. There was a deep porch at the front as well. Most of that is gone now, taken apart or buried over the centuries.

Why did these columns survive when so much else vanished? The answer is reuse. For centuries, Romans treated ancient ruins as a quarry. Marble was burned for lime, and metal clamps were pulled out of the joints. A building only survived if somebody found it useful. In the late seventeenth century, someone did. The papal government turned the old temple into a customs house. The architect Carlo Fontana and his team built the new structure directly into the ancient colonnade.

That customs house collected duties on goods arriving in the city by land. Picture carts and mules unloading here, with clerks checking cargo and stamping papers. The ancient columns became the front of a working government office. It is not a romantic story, but it is a practical one. A temple to a god-emperor became a place for taxes and trade. Because of that, the columns kept their place in the city when they might have been lost.

The building kept changing roles. After Rome became the capital of a united Italy in the nineteenth century, it housed the city's stock exchange. Today it belongs to the Rome Chamber of Commerce. The large interior hall is sometimes used for conferences and exhibitions. So this site has been a temple, a customs office, a market for shares, and a business centre. Very few buildings anywhere have served commerce and faith across so many centuries.

Here is the second surprise. The temple was once decorated with relief carvings of women in different costumes. Each figure represented a province of the Roman Empire. Some wore armour, some wore cloaks, and some held weapons or symbols of their region. Together they showed the size of the world Hadrian had governed. He was famous for travelling through those provinces in person. Several of these panels survive today, but not here. They are kept in museums, including the Capitoline Museums on the Capitoline Hill.

Take a moment to look closely at the column surfaces. You will see scars, cracks, and rough patches where the marble has broken away. Some damage likely came from fire and weather. Some came from people removing stone and metal. Notice too how the newer building sits tightly against the old columns. The join between ancient and modern is right in front of you. In Rome, that join is often hidden. Here it stands in the open, one layer pressed against another.

The square itself is worth a slow look. It is quieter than the busy streets around it, even though Via del Corso is only a short walk away. In the evening, lights shine up onto the columns, and the marble turns warm and golden. People sit at the café tables with a coffee or a glass of wine. Children sometimes chase pigeons across the paving. Few of them glance up. For locals, this two-thousand-year-old colonnade is simply the background of an ordinary day.

Before you move on, stand back near the edge of the square. Let your eye travel slowly from the sunken base, up the long grooves of the columns, to the broken stone at the top. Then look at the windows of the office behind. Think of a son honouring his father, of clerks counting goods, of traders shouting prices. All of it happened on this same spot. As you walk away toward the Pantheon, listen to your footsteps on the stone... and remember how much of the old city still lies beneath them.