La Posta Astro-Geophysical Observatory, Research observatory in San Diego County, United States.

La Posta Astro-Geophysical Observatory was a 60-foot-diameter (18 m) Navy Electronics Laboratory radio telescope at Campo, California, on a 3,900-foot (1,200 m) site in the Laguna Mountains, 65 miles (105 km) east of San Diego. The dish could both transmit and receive; a building at its lower right held a turbine-powered alternator, and an operator in a building beneath the dish controlled it by computer, with movements watched on closed-circuit television. It was dismantled in late 2015.

Construction of the 60-foot dish began in 1964 at a 3,900-foot site in the Laguna Mountains, 65 miles east of San Diego. Its transmit-and-receive capability supported propagation and ionospheric forecasting used during several Apollo launches to predict solar activity that could hamper ground-to-capsule communications. The Navy Electronics Laboratory installation was decommissioned in 1986, and the dish stood unused until it was dismantled in late 2015.

The site's nickname, "the Pterodactyl Birdbath", came from local residents who watched the dish point upward after it was decommissioned in 1986. The dish could both transmit and receive, and its movements were monitored by closed-circuit television from a control room beneath it.

The dish was dismantled in late 2015, so nothing of the installation remains; the surrounding site is now Mountain Warfare Training Camp Michael Monsoor, a military facility, and access is restricted. The location is in the Laguna Mountains at about 3,900 feet (1,200 m) elevation, roughly 65 miles (105 km) east of San Diego near Campo.

The dish could both transmit and receive, and its movements were watched on closed-circuit television by an operator in the building beneath it. Power came from a turbine-driven alternator, since the national grid could not supply enough. Locals called the idle, upward-pointing dish "the Pterodactyl Birdbath".