La Posta Astro-Geophysical Observatory

La Posta Astro-Geophysical Observatory is a research site in the Laguna Mountains roughly 65 miles east of San Diego, which housed a 60-foot radio telescope dish at 3,900 feet elevation. The facility operated using a turbine-powered generator system and was controlled from a building located beneath the dish.

The facility was constructed in 1964 and played an important role monitoring solar activity for Apollo missions, as such activity could disrupt spacecraft communications. Operations ended in 1986, and the structure was eventually dismantled completely in 2015.

Scientists used this facility for studying solar radiation patterns and developed specialized equipment for microwave measurements and ionospheric forecasting. The work carried out here shaped research practices in the region for several decades.

The site sits on a mountain ridge with limited access, so visitors should prepare for unpredictable mountain weather. Since the facility is no longer operational, there is little to see on site, but the location offers views across the surrounding mountain landscape.

After the antenna was decommissioned, local residents gave it the informal nickname 'the Pterodactyl Birdbath' because of its unusual shape. This playful local name stuck in the community's memory until the structure was completely removed in 2015.

Location: San Diego County

Inception: 1964

GPS coordinates: 32.67770,-116.43600

Latest update: December 14, 2025 16:47