 It is the seat of the Spanish National Astronomical Observatory and the Observatorio Geofísico Central, both
administered by the National Geographic Institute (via its department of "Astronomía, Geofísica y Aplicaciones Espaciales").The observatory was designed by Juan de Villanueva, architect to Charles III of Spain, It represents one of the highlights of Spanish neoclassical architecture.Its domed lantern was conceived as a classical circular temple.