Yerkes Observatory

Yerkes Observatory

$The Great Refractor!$

View Gallery

Address:: 373 W. Geneva Street
Williams Bay, WI 53191
Phone:: (262) 245-5555
Visit Website

Book Now

Click to View Map

Details

Tours are available Thursdays through Mondays during summer months and Fridays and Saturdays during the 2026 winter and spring. Limited tickets are available ONLINE ONLY for these curated experiences. Click HERE for more information and to reserve your tour.

Open year round for engaging, comedic, kid-friendly, behind-the-scenes, and transformative tours and programs! This place is one of one in the universe. You don't have to know a thing about astronomy. Our enthusiasm for it is contagious. Our tours feature architecture, landscape design, photography, restoration, American history, engineering, libraries, exhibits, vintage instruments, and more. You get to see the world's largest refracting telescope, the 12,000 lb. Great Refractor with its 40" lenses. You also get to see a selection of glass plate pictures of space from our collection of 180,000 dating back 125 years. For three years in a row, we have been a finalist for the Arts, Culture, and Heritage Award (the state's top tourism prize) at the Wisconsin Governor's Awards for Tourism. This is a can't-miss, must-see experience!

Yerkes Observatory, the birthplace of modern astrophysics, is an 1897 architectural masterpiece on fifty acres of Olmsted-designed ecological splendor. Yerkes has been home to famous astronomers like Edwin Hubble, Carl Sagan, and Nancy Grace Roman and visited by people from around the world such as Albert Einstein who had Yerkes at the top of his bucket list on his first trip to the United States. We're now open for public tours, concerts, telescope nights, art exhibits, arboretum walking, sculpture strolls, open houses, workshops, and more. The world-famous Observatory's beautiful location overlooking Geneva Lake in Williams Bay, Wisconsin is only fifteen minutes from downtown Lake Geneva. We're on a new voyage under the stewardship of Yerkes Future Foundation, a nonprofit 501c3. All proceeds go to the preservation, restoration, and programs of this international landmark of astronomy, architecture, and landscape design. For further information, please visit our website.
Amenities
Weddings

General

Business Continuity
General
- Number of Meeting Rooms: 4
- Alternative Meeting Space:
- Theater Available:
- Banquet Set-up Available:
- Audio/Video Available:
General
- Price Range: $$
- Fall:
- Winter:
- Spring:
- Summer:
- Year Round:
- Level of Difficulty: Medium
- Largest Group Capacity: 100 indoor and 300 outdoor
- Wheelchair Accessible:
- Group Tour:
- Family Fun:
General
- Reduced Occupancy/Occupancy Limits:
- Limited Elevator Occupancy:
- Mobile Payments Accepted:
- Mobile Payments Required:
- CDC Recommended Cleaning Procedures:
- Open For Business:
Meeting Facility
Facility Info
- Exhibits Space
- Reception Capacity 150
- Banquet Capacity 150
- Number of Rooms 5
- Classroom Capacity 130
Events

Yerkes Observatory Open House: Exploring Art

Yerkes Observatory Open House: Exploring Art
May 21, 2026 - May 21, 2026

Summer Solstice Open House at Yerkes Observatory

Summer Solstice Open House at Yerkes Observatory
Jun 20, 2026 - Jun 20, 2026

Yerkes Observatory Open House: The Wonders of Physics

Yerkes Observatory Open House: The Wonders of Physics
Jul 31, 2026 - Jul 31, 2026

International Observe the Moon Night at Yerkes Observatory

International Observe the Moon Night at Yerkes Observatory
Oct 17, 2026 - Oct 17, 2026