The Aztecs lived in a large city called Tenochtitlan. Tenochtitlan was built on an island in the middle of Lake Texcoco. The city was divided into four main districts, each with its own temples, palaces, and markets. The Aztecs lived in houses made of adobe bricks and thatched roofs. The houses were usually small and dark, but they were well-suited to the warm climate of Mexico.