The Olmec civilization is one of the earliest known Mesoamerican cultures, flourishing from around 1200 to 400 BCE in present-day Mexico. They are often referred to as the "mother culture" of later civilizations due to their significant influence on Maya and Aztec societies. The Olmecs are best known for their colossal stone heads, which are believed to represent rulers or important figures. The Olmecs developed a complex society with advancements in agriculture, trade, and art. They created one of the first writing systems in the Americas and made significant contributions to calendar systems and mathematics. Their major urban centers, such as San Lorenzo and La Venta, showcased impressive architecture and monumental sculptures.