Iztaccíhuatl–Popocatépetl National Park

Breathe in slowly. Up here the air is thin and cold, and it smells of pine resin and damp volcanic soil. Underfoot, the ground is dark grey sand, fine as ash, which is exactly what much of it is. Somewhere above you, a pale plume may be rising from a cone-shaped summit. And across the valley, a long white ridge lies against the sky like a sleeping figure under a sheet. Welcome to Iztaccíhuatl–Popocatépetl National Park, the high country of two volcanoes.

This park is one of the oldest in Mexico. It was created in 1935, during the presidency of Lázaro Cárdenas, a leader who set aside many forests and mountains for protection. The park reaches across three states — the State of Mexico, Puebla, and the northern edge of Morelos. So if you came up from the warm valleys of Morelos, you have climbed from sugarcane country and orchards into a world of frost, grass, and stone. That change happens in only a few hours of driving.

Let us start with the names, because they come from Nahuatl, the language of the Aztecs, which is still spoken in villages around these mountains. Popocatépetl means the smoking mountain. Iztaccíhuatl means the white woman. Both names describe what people saw centuries ago, and what you can still see today. One mountain smokes. The other lies white and still. Locals often shorten them with affection, calling them simply Popo and Izta.

These are giants. Popocatépetl is the second highest mountain in Mexico, rising well above five thousand metres. Iztaccíhuatl is the third highest, only slightly lower. Only the Pico de Orizaba, further east, stands taller. On a clear day, people in Mexico City and Puebla can see both summits from their streets and rooftops. For millions of people, these two shapes mark the edge of the sky, the way a coastline marks the edge of the land.

Now look closely at Iztaccíhuatl. Its long ridge has distinct parts, and mountaineers have named them after a human body. There is the head, the chest, the knees, and the feet. The chest is the highest point. Once you see the figure, it is hard to stop seeing it — a woman lying on her back, her hair spread out to the north. This shape is the reason for one of Mexico's best-loved stories.

According to the popular legend, Iztaccíhuatl was a princess, and Popocatépetl was a warrior who loved her. He went away to war. A false message reached her that he had died, and she died of grief. When the warrior returned, he carried her body to the mountains, laid her down, and knelt beside her with a burning torch. Legend has it that he still keeps watch, and the smoke is his torch. It is folklore, of course, but you will see this scene painted on calendars, murals, and restaurant walls across Mexico.

The smoke, however, is very real. Popocatépetl is one of the most active volcanoes in North America. After a long quiet period, it woke up again in 1994, and it has been erupting on and off ever since. Sometimes it sends up gentle steam. Sometimes it throws out ash that falls on nearby towns and even closes airports. Scientists watch it around the clock. For safety, climbing to its crater is forbidden, and access near the cone is restricted.

Between the two volcanoes lies a high mountain pass called Paso de Cortés. The name carries a heavy piece of history. In 1519, the Spanish conquistador Hernán Cortés and his army crossed through this area on their way to Tenochtitlan, the Aztec capital. From these heights, the Spaniards had one of their first views of the great valley and its lake city. Today the pass is the main gateway for visitors, with a visitor station and trails leading out across the slopes.

Here is something many visitors miss. The glaciers on Iztaccíhuatl have been shrinking fast. One of them, the Ayoloco glacier, was declared gone in 2019, and a memorial plaque was placed in its honour. It is a quiet message from the mountain about a warming climate. The snow you may see today is often seasonal, and the permanent ice is much smaller than it was even a generation ago. Older photographs of the white woman show a far whiter figure.

The living world here is just as interesting as the rock. Lower down, there are forests of pine and fir. Higher up, the trees give way to tall, tough bunchgrass that moves like a golden sea in the wind. And in that grass lives a creature found almost nowhere else on Earth — the volcano rabbit. It is tiny, with short round ears, and it makes high whistling calls. Locals call it the teporingo or zacatuche. If you sit still near the grass, you might hear it before you see it.

The lower slopes of Popocatépetl hold another surprise, and this one connects directly to Morelos. In the sixteenth century, Spanish friars built a chain of monasteries in the villages around the volcano. These massive stone buildings, with wide open courtyards for crowds of new converts, are now listed together by UNESCO as World Heritage. Many of them stand in Morelos, in towns such as Tepoztlán and Tetela del Volcán. Seen together with the park, they show how the mountain shaped both faith and daily life.

For the people who live at its feet, Popocatépetl is not only a volcano. In some villages, he is still called Don Goyo, a respected elder of the mountain. Local traditions include offerings and prayers for rain and good harvests, a custom with roots that reach back before the Spanish arrived. Farmers read the clouds on the summit to predict the weather. Here, the line between landscape and neighbour is thin.

Before you go, take one more slow look around. Notice how cold your fingers feel, and how quickly the light changes as clouds pass over the summits. Listen for wind in the grass, and maybe a distant whistle from a small rabbit. Look again at the smoking cone and the sleeping white ridge beside it. People have stood and watched these two mountains for thousands of years — and now, for a moment, you are one of them.