Observatorio Astronómico Nacional Cerro Calán is Chile's historic national observatory and the home of the University of Chile's Department of Astronomy. Founded in 1852 and established on Cerro Calán in 1960, it preserves historic instruments while supporting research, teaching, and public astronomy. Guided visits explain the observatory's telescopes and their contribution to Chilean astronomy; scheduled nighttime programs add observing through on-site telescopes when weather permits, while daytime educational visits serve schools. Visits must be arranged through the department's current booking process.