Palomar Observatory in Southern California became one of the world’s leading astronomical research centers through George Ellery Hale’s vision and Caltech’s development of increasingly powerful instruments. Its 200-inch Hale Telescope, first used in 1949, was the largest in the world for 26 years and contributed to major advances including the Hubble flow, the discovery of distant quasars, and studies of stars and element formation. Other Palomar instruments supported major sky surveys, the discoveries of Eris, Sedna, the first brown dwarf, and Comet Shoemaker-Levy 9. Its influential survey imagery, distinctive Art Deco design, and continued nightly research have made Palomar enduringly significant.