Redonda Mesa is a coastal mesa in the southern Santa Ana Mountains of southwestern Riverside County, near the Pacific and close to the San Diego county line. Though only 2,825 feet high, its summit commands sweeping views across Camp Pendleton, the Temecula Valley, nearby communities, the San Jacinto Mountains, and sometimes Santa Catalina Island. The mesa is covered in coastal sage scrub, an increasingly endangered Southern California plant community. Its broad sightlines also gave it strategic value for communications: in the late 1970s and around 1981, AT&T established a microwave relay tower on a 20-acre summit parcel, creating part of the region’s telephone backbone for about a decade before the site was later converted into a residence.