Teotihuacán is an ancient Mesoamerican city located 30 miles (50 km) northeast of modern-day Mexico City. The city was settled as early as 400 B.C. and became the most powerful and influential city in the region by 400 A.D. By the time the Aztecs found the city in the 1400s and named it Teotihuacan (meaning “the place where the gods were created”), the city had been abandoned for centuries. Teotihuacan’s origins, history, and culture largely remain a mystery. And their technology they used to do that was their huge pyramids that they constructed, and the sun, the stars, the mountains. Their entire city was built in order to track the movement of the celestial bodies.