Lacus Curtius

Look down at your feet. The ground here sits low, and on a wet morning you can still feel the damp rising from the old valley floor. Around you are broken columns, worn paving and the murmur of visitors. Somewhere in this open square, a modest patch of old stone marks one of the strangest places in the Roman Forum. It is the Lacus Curtius, the Curtian Lake. Do not expect water. The lake disappeared long ago. What remains is a memory the Romans themselves could never fully explain.

To understand the name, picture this spot before Rome had marble or temples. The Forum lies in a hollow between hills. In the earliest days, this hollow was marshy ground, with water draining down from the slopes around it. The Romans later channelled that water away through a great drain called the Cloaca Maxima, which still runs beneath the city. Once the drain worked, the swamp dried out, and the valley became the heart of public life. But one wet corner kept its old name.

Here is the first surprise. The Romans did not agree on where the name came from. The scholar Varro, writing in the first century before Christ, recorded three different stories. The historian Livy also told more than one. In other words, even two thousand years ago, this place was already a puzzle. Romans walked past it every day, threw offerings into it, and argued about what it meant. You are standing at the edge of a mystery that is older than most of the ruins around you.

The first story reaches back to the city's legendary founding years. According to the tale, Rome fought a war against the Sabines, a neighbouring hill people. A Sabine warrior named Mettius Curtius rode into battle here. His horse sank into the marsh, and he struggled out of the mud with difficulty. The swamp, the story says, took his name. It is a muddy, unheroic origin, and perhaps that is why many Romans preferred a grander version.

That grander version is the one most visitors hear. Legend has it that one day the ground in the middle of the Forum split open. A deep chasm appeared, and nothing could fill it. Soothsayers declared that the gap would close only when Rome threw in its most precious possession. A young soldier named Marcus Curtius understood the answer. Rome's greatest treasure, he said, was the courage of its men. He put on his armour and mounted his horse.

Then, according to the story, he rode straight into the pit. The earth closed over him, and the city was saved. Livy places this event in the fourth century before Christ. Historians today treat it as legend, not a record of a real event. But for Romans, it was a powerful lesson about sacrifice for the community. Parents told it to children. Writers repeated it for centuries. And this unremarkable square of ground became, in their minds, the place where it happened.

The third story is the least dramatic, and it may be the closest to the truth. In this version, lightning struck the spot during the consulship of a man named Gaius Curtius. Romans treated ground hit by lightning as sacred, touched by the gods. Such places were fenced off and left untouched. So the Curtian Lake may simply be a holy enclosure, protected because the sky once marked it. Three stories, then: a stuck horse, a heroic leap and a bolt of lightning.

Whatever the origin, the Romans kept this spot special. The writer Suetonius records a striking custom under Augustus, the first emperor. Every year, people of all ranks threw a coin into the Lacus Curtius as a vow for the emperor's health. Think about that for a moment. In the middle of the busiest square of the ancient world, Romans tossed coins into a sacred pit. Visitors today throw coins into the Trevi Fountain, not far from here. The habit is much older than that fountain.

This spot also saw real violence. In the year 69, a year of civil war, the emperor Galba was attacked and killed in the Forum. Ancient writers, including Tacitus and Suetonius, place his death near the Lacus Curtius. Galba had ruled only a few months. Soldiers who had turned against him caught him here, in the open, surrounded by the monuments of Roman power. The legend of a man sacrificed for the city sat beside the memory of a ruler cut down by his own army.

Now look at what survives. The remains are low and easy to miss. You will see an area of old paving with an irregular outline, set slightly apart from the paving around it. Archaeologists have identified several layers here, built at different times as the Forum floor rose and was rebuilt. It is not grand. Many people walk straight past it on their way to larger monuments. But that modesty is part of its character. Sacred places in early Rome were often simple.

The second surprise is a carving. In the sixteenth century, a marble relief was found near here. It shows a rider on a rearing horse, plunging downward, often identified as Marcus Curtius making his leap. The original is now kept in the Capitoline Museums, on the hill above the Forum. A copy has been placed near the site, so you can see the image where the story belongs. Look at the horse's raised legs and the rider leaning into the fall.

Take a moment to look around you from this spot. The Forum rises in layers of history on every side. Columns stand alone where whole temples once stood. The Palatine Hill climbs to one side, and the Capitoline to another. Imagine the same view crowded with senators, merchants, soldiers and priests. Imagine the noise of speeches and trading. And imagine someone stopping here, in the middle of all that, to drop a small coin into the ground for luck.

Before you move on, look down once more. This is lower ground, the floor of an old marsh that Rome turned into a city centre. Under the paving, water still runs through ancient channels. Above it, people still pass, many of them unaware of the stories here. Perhaps that suits the place. The Curtian Lake was always more about memory than stone. As you walk away, notice how the ground slowly rises beneath you, out of the old hollow and back into the present.