What was a significant infrastructure feature that connected Tenochtitlan to the mainland?

The significant infrastructure feature that connected Tenochtitlan to the mainland was the causeways. These causeways were engineering marvels that played a crucial role in the functioning of Tenochtitlan, which was situated on an island in Lake Texcoco. The causeways allowed for the movement of people, goods, and troops between the city and the surrounding mainland.

Constructed from earth and stone, they were elevated above the water level of the lake, offering a stable and direct path to and from the city. The causeways also featured gaps that could be used as canals, which facilitated the transportation of goods via canoes. This system of causeways not only enabled trade and communication but also helped in defending the city against potential attacks, as they could be easily fortified.

In contrast, while roads and bridges are important forms of infrastructure, they do not specifically refer to the unique design and function provided by the causeways in the context of Tenochtitlan. Highways are a modern concept that did not exist in the ancient world of the Aztecs. Thus, causeways were an essential and defining feature of Tenochtitlan's infrastructure, distinctly connecting the island city to the mainland.