Cuicuilco

Listen first. Beyond the trees, the traffic of southern Mexico City moves in a low, steady roar. Under your feet the path is gritty, and at its edges the ground turns dark grey and broken, full of small holes like a sponge. That rough black rock is cooled lava. In front of you rises a wide, round mound of earth and stone. It has no sharp corners and no tall peak. This is Cuicuilco, one of the oldest monumental sites in the Valley of Mexico.

Most pyramids in Mexico are square at the base, with steep sides and a temple on top. Cuicuilco is different. Its main structure is circular, built in stacked rings that grow smaller as they rise, like a cake with its top cut flat. Walk slowly around the base and you will see how the curve never breaks. Ramps once led up to the summit, where people almost certainly held ceremonies. The shape alone tells you that you are looking at something very early, from before the great cities that came later.

How early? Archaeologists place Cuicuilco in the Formative period, sometimes called the Preclassic. That is the long era when farming villages in central Mexico grew into the first towns with temples and public plazas. People were living here many centuries before the common era. At its height, Cuicuilco was one of the largest settlements in the whole valley. For a time it was probably the most important one, long before the Aztecs, and even before the city of Teotihuacan reached its full size.

Now look again at that black rock around you. It came from a volcano called Xitle, a small cone that rises in the hills to the south. In the early centuries of the common era, Xitle erupted. Lava flowed north across the land and covered a huge area, including much of Cuicuilco. Scholars still debate the exact date of the eruption, and new studies keep refining it. What is clear is that the lava sealed the lower parts of the town under a thick crust of stone.

Here is a detail many visitors miss. The decline of Cuicuilco may have begun before the lava arrived. Earlier volcanic activity, ash, and changes in the land may already have pushed people to leave. Many archaeologists think that some of these families moved north and east across the valley. If so, the fall of Cuicuilco helped feed the growth of Teotihuacan, the great city of pyramids that later dominated central Mexico. One city faded while another rose, and a volcano sat between their stories.

The lava that destroyed the town also protected it. For many centuries the site lay half hidden under rock and scrub. In the early 1920s, an American archaeologist named Byron Cummings led excavations here. His team had to cut through the hard volcanic crust to reach the old walls beneath. Imagine digging not through soft soil, but through stone that had once been liquid fire. In places you can still see the line where the lava wrapped around the base of the pyramid.

The people of Cuicuilco left behind pottery, small clay figurines, and tools. One figure connected with this early period is often called the Old Fire God, known in later Aztec tradition as Huehueteotl. He appears as a bent, elderly man carrying a large brazier, a bowl for burning fire, on his head or shoulders. It is easy to see why many people link such a god to a community living so close to an active volcano. Fire was not abstract here. It lived in the hills.

You may hear that the name Cuicuilco means place of song and dance. That is the most common popular translation from Nahuatl, the language of the Aztecs. But Nahuatl was spoken here much later, so the name was given by later peoples. Nobody knows what the original builders called their own town, or even with certainty which language they spoke. That small gap is worth holding in mind. Even the name you see on the signs is a later layer.

Step back and look at the setting. The landscape around you is called the Pedregal, which simply means a stony place. The lava field from Xitle stretches across a large part of southern Mexico City. Nearby, the main campus of the National Autonomous University of Mexico was built on the same rock. Parts of the old lava field there are now protected as a nature reserve. The plants you see at Cuicuilco grow in thin pockets of soil between the stones.

Look closely at that vegetation. You will find agaves with thick, spiky leaves, low cactus, wild grasses, and small shrubs that survive on very little water. In the rainy season, flowers appear in the cracks of the rock and the site turns surprisingly green. In the dry months, the colours fade to gold and grey. Lizards often rest on the warm lava. Birds move through the trees. In the middle of a giant city, this is a quiet island of older ground.

There is also a modern story here, and it is less peaceful. Cuicuilco once covered far more land than the area you can visit today. Over the twentieth century, the city grew right up to its edges. Roads, housing, a shopping centre, and office towers now stand on ground that was once part of the ancient settlement. Their construction caused public protests and long arguments about protecting the past. The fenced area around you is the part that survived those battles.

If the small site museum is open during your visit, it is worth a few minutes. It helps you picture daily life in an early farming town, with its cooking pots, figures, and simple tools. Then return to the pyramid and climb the paths that lead up and around it, where access is allowed. From the upper levels, turn south. On a clear day you may see the green hills where Xitle stands, the source of the lava under your feet.

Take a moment at the top. Around you, the city hums on every side, and the towers of the modern avenues rise above the trees. Below you is a round platform of earth and stone that people raised by hand, long before any of that existed. They built it, used it, and then watched fire come down from the hills. The rock they feared is now the ground that keeps their work in place.

As you walk back down, notice the edge where the dark lava meets the pale stones of the pyramid. Listen to the traffic again, and the wind in the dry grass. You are standing at one of the beginnings of this valley's long story, before Teotihuacan, before the Aztecs, before the colonial city and the modern one. Take your time on the way out. Every step across the black stone is a step across a very old morning.