Tenochtitlan was founded in 1325 and became the capital of the Aztec Empire. Built on the island in Lake Texcoco, it grew into one of the largest cities in the world, with canals, temples, markets, and an advanced urban system that amazed the Spanish conquerors.

The city stood on an island toward the western shore of the lake, connected to the mainland by a network of causeways. Over time, the Aztecs built and reinforced these raised roads with stone, earth, and wooden piles, creating sturdy connections to nearby islands and the shore.

This location gave the city strong natural defenses while providing easy access to surrounding markets, waterways, and fertile lands. The causeways allowed people to transport goods, obtain food, and connect efficiently with neighboring towns and resources.

These causeways were more than just roads. They allowed travel and trade across the lake and shaped the daily life of the Aztec capital. Each one became an essential lifeline, linking Tenochtitlan to surrounding regions and helping it thrive for centuries.

Causeways of Tenochtitlan

The causeways were massive stone and earth structures built to link the island city with the nearby small islands and the mainland. Constructed in the late 14th century, they were crucial for transport, defense, and the growth of the Aztec capital across Lake Texcoco.

Engineers used wooden piles carefully driven into the lakebed, then filled the gaps with stone and earth. This created solid foundations strong enough to hold thousands of people and even allow troops, animals, and goods to cross safely in every season.

The causeways also included sluice gates and small bridges. These openings allowed canoes to pass through and water to circulate naturally. In times of war, the removable bridges could be removed, turning the roads into defensive barriers protecting the island city.

At its height, Tenochtitlan had five major causeways, recorded by historians. They reached toward Tacuba, Chapultepec, Coyoacán, Tepeyacac, and Iztapalapa. Each road was vital, ensuring steady supplies, trade, and communication across the city and its allied towns.

After the fall of Tenochtitlan

When the Spanish finally conquered Tenochtitlan in 1521, the ancient causeways became critical routes for rebuilding the city. The new colonial capital of Mexico City rose directly on the ruins, and these historic roads now served as the city’s main arteries.

Over the centuries, the lake was gradually drained, canals slowly disappeared, and neighborhoods expanded across the former water. Yet the lines of the causeways remained. They defined the city’s growth, guiding how streets and districts developed over time.

These old roads became witnesses to history and major events. They saw the dramatic fall of an empire, the rise of Spanish rule, independence, and modern urban expansion. Even today, their historic routes carry millions of people through Mexico City’s busy daily life.

Nearly seven hundred years have passed since the first Aztec causeways were built. Despite countless changes and transformations, their paths endure. What once were raised stone roads across water are now wide avenues and highways crossing the modern capital.

Modern equivalents of the causeways

One of the main Aztec roads was the causeway to Tlacopan, today known as Calzada México-Tacuba. This historic route once carried warriors and traders west across the lake. Now it is a busy urban avenue that links the historic center with Tacuba and the northwestern districts.

Another important route was the northern causeway to Tepeyacac. Today, it survives as Calzada de los Misterios, leading directly to the Basilica of Guadalupe. Once a sacred path for Aztec pilgrims, it is now one of the city’s most symbolic and spiritual roads.

The causeway to Iztapalapa ran southeast, ensuring secure access to fertile lands and friendly allies. It became Calzada de Iztapalapa, which still connects central Mexico City with the historic borough. Its long path preserves a direct tie with ancient traditions.

To the south stood the causeway to Coyoacán, later transformed into Calzada de Tlalpan. Once a vital Aztec lifeline, it is now a major urban highway lined with stadiums, markets, and neighborhoods, yet still following the original direction of the Mexica road.

The southwest causeway reached Chapultepec, source of the city’s fresh water. Today, this road is Avenida Chapultepec, one of the busiest main arteries in Mexico City. From sacred springs to modern traffic, it has always supplied the capital’s essential needs.

Living roads: Aztec causeways in Mexico City

These ancient causeways did not disappear after the fall of Tenochtitlan. Over centuries, they survived conquest, colonial urban expansion, and modernization. Today, they remain central roads, guiding traffic, neighborhoods, and city life along paths first laid by the Aztecs.

The original Aztec causeways endured through centuries of dramatic change. Even as canals were drained and new streets built, their lines continued to shape the growth of Mexico City, preserving a link between the ancient island capital and modern urban life.

These roads became silent witnesses to history, surviving colonial rule, independence, and rapid urbanization. Today, travelers, commuters, and tourists walk and drive along these ancient routes, following the same paths once used by Aztec warriors and traders.

Calzada México-Tacuba (Tlacopan causeway)

The causeway to Tlacopan was one of the most strategic roads in the Aztec Empire. It connected Tenochtitlan with allies in the west and provided a vital supply route. Spanish forces also used this main causeway during their siege, making it central in the city’s conquest.

Over centuries, this ancient Aztec causeway gradually evolved into Calzada México-Tacuba. It remains a busy urban corridor linking downtown with the northwest. Along its long path stand monuments and neighborhoods, preserving a memory of its Aztec and colonial past.

Calzada de los Misterios (Tepeyacac)

The northern causeway to Tepeyacac once carried Aztec pilgrims to sacred sites near the hill of Tepeyacac (modern Tepeyac). This raised road served both spiritual and practical purposes, maintaining a vital connection with communities beyond the island city of Tenochtitl

Today, it survives as Calzada de los Misterios, leading directly to the Basilica of Guadalupe. The historic avenue blends pre-Hispanic devotion with Catholic tradition, making it one of the most symbolic and culturally rich routes for modern residents and visitors in Mexico City.

Calzada de Iztapalapa (Iztapalapa)

The causeway to Iztapalapa connected Tenochtitlan with fertile chinampa fields and neighboring towns. This road was essential for transporting food supplies and supporting military campaigns, giving Tenochtitlan secure access to its southeastern allies and productive lands.

This route became Calzada de Iztapalapa. The modern road remains vital, linking central Mexico City with its historic borough. Daily life continues along the same path that once carried maize, warriors, and traders into the heart of the Aztec capital over centuries.

Calzada de Tlalpan (Coyoacán)

The southern causeway to Coyoacán provided access to allied towns and markets beyond the lake. During the Spanish conquest, this raised road became one of the battlegrounds where the Aztecs resisted the invading forces advancing toward the island city center.

Now it is Calzada de Tlalpan, a major urban highway. It connects the historic center with the southern districts. Estadio Azteca and old colonial towns line its route, showing how an ancient Aztec causeway adapted over centuries to modern urban needs and traffic.

Avenida Chapultepec (Chapultepec)

The southwest causeway reached Chapultepec, where springs supplied fresh water to the capital through aqueducts. This road was one of the most important lifelines for sustaining Tenochtitlan’s population, supporting daily life, trade, and essential resources across the lake.

Today, it is Avenida Chapultepec, one of Mexico City’s busiest main arteries. Surrounded by nightlife, offices, and historic monuments, it continues to preserve the vital role of connecting people, water, and goods, just as it did for the Aztec capital centuries ago.

Conclusion

The ancient causeways of Tenochtitlan remain a living and historic part of Mexico City. Over seven long centuries, they transformed from raised stone roads across water into major urban avenues, yet their original paths still shape the city’s structure and daily flow.

These historic roads witnessed the rise and fall of empires, the Spanish conquest, the colonial times, and centuries of urban growth. Today, they connect neighborhoods, markets, and cultural landmarks, allowing modern life to move along routes first laid by the Aztecs.

Walking or driving along these historic avenues, people follow the same lines that once carried warriors, traders, and devoted pilgrims. The causeways are not just ordinary streets but enduring symbols of history, connecting the past and present of Mexico City.

From Tacuba to Chapultepec, each ancient road tells a remarkable story. They remind us that beneath the modern city lies a network of ancient engineering, vision, and culture. The Aztec causeways continue to guide movement and memory in the heart of the capital.