East Campus, occupying approximately , hosts the core cluster of academic buildings and services. The original buildings that formed the earliest kernel of the campus included the UC Citrus Experiment Station, residential buildings, and barn, all of which are still in use. They were designed by Lester H. Hibbard, in association with H.B. Cody. Built by 1917 at a cost of $165,000, the architecture of the major buildings followed the Mission Revival style suggesting the Spanish colonial heritage of Southern California.