Teotihuacán is an ancient Mesoamerican city located in the Basin of Mexico, about 30 miles (50 kilometers) northeast of present-day Mexico City. It is one of the most significant archaeological sites in Mexico and is known for its impressive pyramids and monumental architecture. Here are some key aspects of Teotihuacán:

1. Pyramids of the Sun and Moon: The Pyramids of the Sun and Moon are the two main structures at Teotihuacán. The Pyramid of the Sun is one of the largest pyramids in the world, and the Pyramid of the Moon is positioned at the northern end of the Avenue of the Dead. Both pyramids played important roles in the religious and ceremonial life of Teotihuacán.
2. Avenue of the Dead: This broad, central avenue runs through the heart of Teotihuacán, connecting the Pyramid of the Moon to the Pyramid of the Sun. It is flanked by various smaller structures, including the Temple of the Feathered Serpent (also known as the Temple of Quetzalcoatl).
3. Temple of the Feathered Serpent: This temple is dedicated to the Mesoamerican deity Quetzalcoatl, often depicted as a feathered serpent. It is adorned with intricate carvings and sculptures, showcasing the city’s artistic and religious significance.
4. Citadel: The Citadel, also known as the Ciudadela, is a large square with the Temple of the Feathered Serpent at its center. It served as a focal point for ritualistic and administrative activities.
5. Palace of the Jaguars: Located along the Avenue of the Dead, the Palace of the Jaguars is a complex with several rooms, platforms, and courtyards. It is named after the jaguar motifs found in its architecture.
6. Teotihuacán Murals: Teotihuacán is renowned for its well-preserved murals, found in various structures across the site. These murals depict scenes of daily life, religious ceremonies, and mythological narratives, providing valuable insights into the culture of the ancient city.
7. Museum of Teotihuacán: The onsite museum, known as the Museo de Sitio Teotihuacán, displays artifacts and exhibits related to the history and culture of Teotihuacán. It provides additional context for visitors exploring the archaeological site.
8. Tunnel System: Archaeologists have discovered an extensive tunnel system beneath the Pyramid of the Feathered Serpent, revealing intricate chambers and artifacts. The tunnels shed light on the city’s construction methods and may have had ritualistic purposes.
9. Teotihuacán Culture: Although the builders of Teotihuacán remain somewhat mysterious, it is believed that the city was a multiethnic and cosmopolitan society that influenced subsequent Mesoamerican cultures.
10. UNESCO World Heritage Site: Teotihuacán was designated as a UNESCO World Heritage Site in 1987 due to its outstanding cultural and architectural significance.

Teotihuacán reached its peak between 150 BCE and 450 CE and was one of the largest cities in the ancient world. Its impressive structures continue to captivate visitors, offering a glimpse into the advanced urban planning and cultural achievements of ancient Mesoamerican civilizations.