The interior of LOS ARCOS was done in the grandest Spanish Colonial style. Artisans from Guadalajara and Mexico City were hired to hand-craft various details, such as the stained-glass sunburst suspended inside this octagonal Center Court skylight.
Photo from Petley Studios, Incorporated

The mall's only expansion enclosed a Sears Wing entry hall (in gray). This was completed in late 1979. The mall's only renovation, in 1989-'90, spruced up its interior. A Food Court was created along with the Los Arcos Marketplace (a fancy name for carts and kiosks installed along the two shopping concourses). With these improvements, the complex spanned 607,000 leasable square feet and housed seventy-three stores.