Teotihuacan was one of the largest and most mysterious cities of the ancient world. At its peak around 450 CE, it housed over 125,000 people, making it larger than most European cities of the time. The city is famous for its 'Avenue of the Dead,' a long central thoroughfare flanked by the massive Pyramid of the Sun and the Pyramid of the Moon. Unlike many civilizations, the identity of the people who built Teotihuacan remains unknown; even the name 'Teotihuacan' was given to it by the Aztecs centuries after it was abandoned, meaning 'The Place Where Gods Were Born.' The city was a major manufacturing hub, particularly for obsidian tools, which were traded across Mesoamerica. Its influence is found in Maya architecture and art hundreds of miles away. The city was eventually burned and abandoned around 750 CE, leaving behind a legacy of urban planning and monumental architecture that continues to awe visitors.