The occupants of cars and buses speeding along the city's Anillo Periférico (southern beltway) are sometimes surprised to see an ancient, conical pyramid rising just off the side of the highway, standing out rather strangely among the modern buildings that dominate the surrounding landscape of the city's Pedregal area. From around 1400 to 200 BC, a Mexica settlement with as many as 20,000 residents thrived here along the southern shoreline of Lake Texcoco, the now drained body of water on which Mexico City now stands. They built this impressive pyramid likely around 800 BC, several centuries before the construction of the massive pyramids of Teotihuacán (a settlement that some believe was created by descendants of Cuicuilco inhabitants). It's thus considered the oldest of the major archaeological sites in metro CDMX. Today you can visit the site, which has been remarkably well preserved in part because it was covered in lava by the eruption of nearby Xitle around 100 BC. A small museum designed by noted Mexican architect Luis Macgregor Krieger houses excellent exhibits tracing the settlement's history as well as countless pots, figurines, tools, and other artifacts unearthed on the site. You can also walk the grassy, verdant grounds and stand atop the pyramid. Cuicuilco is a five-minute drive from Tlalpan Centro and about a 15-minute drive from UNAM and Ciudad Universitaria. You can Uber here, or take the Insurgentes Sur Metrobus to the Villa Olímpica stop, from which it's an easy five-minute walk.