The archaeological zone of El Salvador larger is that of Chalchuapa, since it was originally a settlement that today includes the ruins of Tazumal, Casa Blanca, and El Trapiche. Its long occupation starts from the early Pre-classic, according to data collected in the lagoon of Cuzcachapa, which is the main source of water. Middle Pre-classic is important to the presence of an Olmec-style sculpture, on the site of La Victoria, and which currently exhibits at Tazumal. The settlement in Chalchuapa arrives on a monumental scale during the late Pre-classic where today are located the sites of Casa Blanca and El Trapiche. The main structure of El Trapiche is 23 m high and is the highest in El Salvador. At its base was found the Monument 1, which contains a hieroglyphic inscription and a human figure with Epi-Olmec features. Recently it was found in this area two heads of jaguar, which correspond to a sculptural tradition in Western El Salvador. In the E3-7 structure found a burial of 33 individuals who were bound and slaughtered, which not only is one of the earliest evidences of human sacrifice, but reflects that they resorted to the domain military to control the area.

To this period also belong the structures of the site known as Casa Blanca, which consists of a platform of approximately 200 x 200 m, which held six buildings built from Earth and clay. On your side East and North are pyramidal structures, of which highlights the structure 1, 10 m high and the 11 m high structure 5. The other buildings are short and wide, platforms that could support non-perishable buildings for residential and administrative purposes. During the classic period, the population of Chalchuapa concentrated in what is now Tazumal, where imposing buildings were erected. Structure B1-1 is the largest, which covers two hectares and rises by 24 m above the plaza level. Its latest version, visible today, was the result of 13 stages have been accumulated from the 2nd century A.D., although most of its architecture dates from the late classic period. On the north side of the basement is an elongated structure type “Palace” that could well function as a residence during the early classic period. Northwest is the ball-game court, of large dimensions. The Estela de Tazumal is one of three stone sculptures that were at the site, and now is located in the National Museum of anthropology. The relief portrays a character holding a scepter, whose hit shows Mexican deity Tlaloc. In the Post-classic period, adds the B1 – 2 with “Toltec-style” structure and other cultural expressions as the Chac Mool altar and effigies of the god Xipe Totec, which are from influences from the Central Highlands of Mexico are. At the time of the Spanish conquest the region of Chalchuapa was occupied by a population Poqomam Maya.

At Casa Blanca, there is “Archaeological window”, which corresponds to an excavation showing different levels of human occupation, as well as the “Tierra Blanca Joven” (TBJ), which is a layer of earth white color, which was deposited as a result of the eruption of the Llopango volcano in 536 A.D.