The University of Chicago established the Yerkes Observatory as their center for Astronomy and Astrophysics in the 1890's. Located in a beautiful parklike setting, Yerkes Observatory is home to the 40-inch Refractor, largest lens-type telescope in the world. Today we offer many programs for all ages and interests year-round, day and night, including general and special tours, and, evening stargazing, including opportunities to observe through a two-foot diameter telescope.