Yerkes Observatory

The Yerkes Observatory is an astronomical research facility in Williams Bay on Geneva Lake housing one of the largest refracting telescopes in the world. The main instrument measures 40 inches (about 1 meter) in diameter and sits inside a rotating dome of steel and glass.

The University of Chicago founded the facility in 1897 under astronomer George Ellery Hale, who initiated construction of what was then the largest refracting telescope. After more than a century of university management, the Yerkes Future Foundation took over in 2018 and opened the grounds for public education programs.

The architecture combines Romanesque arches with Beaux-Arts details, including carved wood paneling and stained glass windows in the working areas. Visitors today still see the historical instruments and desks where several generations of astronomers documented observations.

Tours include access to the main dome and adjacent research rooms, with guides explaining scientific work and architectural design. The visit suits all ages as the pathways are mostly level and require navigating only a few staircases.

Frederick Law Olmsted and Calvert Vaux designed the surrounding parkland with curving paths and tree clusters following the same principles they used in New York. The grounds offer open views toward Geneva Lake and originally served as a retreat for scientists between observation nights.

Location: Williams Bay

Inception: 1895

Elevation above the sea: 334 m

GPS coordinates: 42.57028,-88.55667

Latest update: December 17, 2025 10:49