Casa Grande is the large remains of a building in a village constructed by the Hohokum. There are two small openings that are set in the sides of the building -- on the Summer Solstice and the Autumnal Equinox, the rays of the sun shine onto the opposite wall inside the structure. There are remnants of some smaller buildings too.
The structure that covers and protects Casa Grande was designed by Frederick Law Olmstead, Jr., and now it also has historical significance. From a distance, it reminded us of a space ship.