Read the text. “The Aztecs settled in the Valley of Mexico—where Mexico City now is—in the 1300s. They built their capital, Tenochtitlán, on an island in the middle of a lake. With 150,000 people, the city was the largest ever built by American Indians. It was, in fact, one of the largest cities in the world at that time. It had advanced engineering and a complex economy.” Based on this passage and on what you know about Spanish colonialism, what do you think Spanish explorers thought when they first saw Tenochtitlán