The
national monument consists of the
ruins of multiple structures surrounded by a compound wall, constructed by the ancient people of the Hohokam period. They farmed the
Gila Valley in the early 13th century. Archeologists have discovered evidence that the people of the ancient Sonoran Desert, who built the Casa Grande, also developed wide-scale irrigation farming and extensive trade connections which lasted over a thousand years until about . "Casa Grande" is
Spanish for "big house" (''Siwañ Wa'a Ki:'' in
O'odham). These names refer to the largest structure on the site, which is what remains of a four-story structure that may have been abandoned by 1450. The structure is made of
caliche, and has managed to survive the extreme weather conditions for about seven centuries. The large house consists of outer rooms surrounding an inner structure. The outer rooms are all three stories high, while the inner structure is four stories high. The structures were constructed using traditional
adobe processes. The wet adobe is thicker at the base and adds significant strength. Noticeable horizontal cracks define the breaks between courses on the thick outer walls. The process consisted of using damp adobe to form the walls and then waiting for it to dry, and then building it up with more adobe. Casa Grande contained a ball court much like that found at the
Pueblo Grande Ruin and Irrigation Sites. Father
Eusebio Kino was the first European to view the Hohokam complex in November 1694 and named it Casa Grande.
Graffiti from 19th-century passers-by is scratched into its walls, though this is now illegal. Casa Grande now has a distinctive modern roof covering built in 1932. ==Administrative history==