Upano Valley Sites

Stand still for a moment and feel the ground beneath you. It is soft, a little springy, and darker than you might expect. Much of this soil is volcanic ash, laid down layer after layer over many centuries. Around you, the air is warm and heavy with moisture. Birds call from the forest edge. Somewhere to the west, often hidden in cloud, a volcano is breathing. This is the Upano Valley, in the Amazonian foothills of eastern Ecuador.

At first glance, the valley looks like farmland and forest. You see pasture, scattered trees, and low green humps rising from the grass. It is easy to walk past those humps without a second thought. But many of them are not natural hills. They are earthen platforms, shaped by people more than two thousand years ago. Under the grass and the ash, this valley holds the remains of one of the oldest known urban landscapes in the Amazon.

For a long time, outsiders believed the Amazon could never have supported large, settled societies. The soil was thought too poor and the forest too dense. The image was of small, mobile groups who left little behind. The Upano Valley helped to change that picture. Here, archaeologists found evidence of planned settlements, roads, and fields. The people who lived here did not simply survive in the forest. They organised it.

The key figure in this story is the French archaeologist Stéphen Rostain. He began working in the valley in the 1990s and spent decades excavating mounds by hand. Before him, an Ecuadorian priest and researcher, Pedro Porras, had already studied a large mound site here, now often called Sangay or Huapula. Both men knew that something large lay under the vegetation. But on foot, in thick growth, it was very hard to see how all the pieces connected.

The breakthrough came from the air. Researchers used LiDAR, a laser survey carried on an aircraft. The laser pulses pass through gaps in the trees and measure the shape of the ground below. When the results were published in the journal Science in 2024, the picture surprised many specialists. The survey showed more than six thousand earthen platforms. It also showed plazas, terraces, drainage channels, and long, straight roads linking one cluster of mounds to another.

Think about what that means as you look across the valley. The platforms were not scattered at random. Many are rectangular and arranged in groups around a low central square. Archaeologists think houses and ceremonial buildings once stood on top of them, made from wood and plant materials that have long since rotted away. The platforms lifted these buildings above wet ground. The plazas between them were open spaces for daily life, gatherings, and probably ritual.

The roads are perhaps the most striking detail. They were dug into the ground and lined with raised banks of earth. Some run for many kilometres, and they keep a remarkably straight line even across uneven terrain. Here is something most visitors miss. These are not narrow forest trails. They are wide, deliberate routes, built with effort and planning. They tied separate settlements into a single network, much like the streets and highways of a modern region.

Between the settlements, the survey also found traces of farming. There were drainage ditches and small rectangular fields, likely used for crops such as maize, manioc, and sweet potato. The volcanic soil here is more fertile than in much of the lowland Amazon. That fertility, combined with careful water management, helped to feed a large population. Researchers estimate that the main period of construction lasted roughly from around 500 BC to somewhere between 300 and 600 of our era.

Who were these builders? Archaeologists link the early phase to what they call the Upano culture, named after the river that runs through this valley. A later group, known as the Kilamope culture, also left its mark here. Pottery helps to tell them apart. Upano ceramics often carry painted red lines and incised decoration. We do not know what these people called themselves. Their language and their names for these places are lost.

Now look west, toward the high peaks of the Andes. On a clear day, you may see a cone with a thin plume of smoke. That is Sangay, one of the most active volcanoes in Ecuador. Its eruptions over the centuries spread ash across this valley. That ash both fed the soil and buried the platforms. In a quiet way, the volcano helped to create this society and then helped to hide it from later eyes.

Why did the settlements decline? The honest answer is that researchers are still debating it. Volcanic activity is one possibility. Changes in climate, conflict, or shifts in trade could also have played a part. There is evidence of later reoccupation by other groups, who lived on and around the older mounds. What is clear is that the forest slowly returned. Trees and grass covered the platforms, and the valley kept its secret for centuries.

Today, this is also the homeland of the Shuar people, an Indigenous nation of the Amazonian foothills. The nearby town of Macas, the provincial capital, is a common base for visitors. The Shuar are not the documented descendants of the Upano builders, and it is important not to blur those histories. But their presence is a reminder that this forest has never been empty. People have lived, farmed, and travelled through this valley for a very long time.

Visiting here is different from visiting a stone ruin. There are no towering temples or carved walls to photograph. What you will see are soft mounds, shallow depressions, and the straight edge of an old road under the grass. Much of the land is private or protected, so it helps to go with a local guide. Bring rain gear, sturdy shoes, and patience. The understanding grows slowly, step by step.

Before you leave, look once more at the humps in the grass around you. Imagine wooden houses on top of them, smoke from cooking fires, and people walking the straight roads toward the next plaza. Listen to the birds and the insects in the trees. Feel the dark soil under your shoes again. You are walking on the floor of a very old city. It is still here, just beneath the surface.