Casma is a city in the Ancash Region, Peru. It is located in the Casma Valley. Its surface has 1 204,85 km². Its people venerate saint Santa Maria Magdalena and its day is celebrated on July 22. Some of the largest prehistoric monuments around the World are situated in the Casma Valley and in the Sechín Valley.
The pyramid, main square, and circular sunken courtyard complexes extend over one kilometer in length. In February 2008 archaeologists uncovered a ceremonial plaza which has been dated to 5,500 years ago, making it one of the oldest structures ever found in the Americas.