The Pyramid of the Sun is a large ancient structure located in the Teotihuacan archaeological site in Mexico. It is one of the largest pyramids in the world, standing about 65 meters tall. Built around 200 AD, it is made of stone and earth, and its base covers approximately 40 acres. The pyramid is aligned with the sun, and it is believed to have been a significant religious and cultural center for the Teotihuacan civilization. Visitors can climb its steps to enjoy panoramic views of the surrounding area, including the nearby Pyramid of the Moon.