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Yerkes Observatory

373 W Geneva St, Williams Bay, WI 53191-9603
+1 262-245-5555
Review Highlights
Tour of Yerkes Observatory

The one-hour guided tour of this historic and scientifically significant site was spectacular. The... read more

Reviewed 4 days ago
Fontana, Wisconsin
History & future of the Universe

Wonderful experience for anyone even vaguely interested in stars, planets, galaxies & the people... read more

Reviewed 1 week ago
David K
Read all 213 reviews
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Yerkes Observatory is owned and operated by the University Chicago, Department of Astronomy and Astrophysics, and located in Williams Bay, Wisconsin. Built between 1895 and 1897 in the classic Romanesque style, Yerkes is home to the largest refracting (lens-type) telescope in the world and two other research-grade reflecting (mirror-type) telescopes. The building is beautifully preserved and ornamented with Roman brick and terra cotta, has three telescope domes (the largest is 90 feet in diameter and 10 stories in height), and is situated on 77 acres in a park-like setting. Tours of the building and the refractor are available Monday through Saturday. The cost is $10 per person age 18+ and $8 per person age 6 - 17. Weekday and Saturday hours vary by season. Consult the website for the most current tour schedule. Saturday tours are held for the public at 10 and 11 am, and 12Noon (11 am and 12Noon only from January 1 to mid-March). Reservations are not required. Saturday visitors are asked for a donation of $10 per person for adults and $8 per person for ages 6 - 17. The grounds are open every day, during daylight hours, for self-guided walking tours, free of charge. Photography is permitted. Professional photographers are required to contact the Observatory in advance during weekday hours to obtain permission for any photo shoot. The staff also hosts public observing sessions with the 40-inch refractor and the 24-inch reflecting telescopes many evenings throughout the year. Reservations are required and there is a charge for participation. Visit the Yerkes website for more information. The Observatory contains a lovely museum, many interesting displays concerning its construction, history, architecture and the science of astronomy, and a beautiful new gift shop with many unique items.
  • Excellent78%
  • Very good19%
  • Average1%
  • Poor1%
  • Terrible1%
Travellers talk about
“tour guide” (23 reviews)
“lake geneva” (26 reviews)
“saturday tour” (6 reviews)
373 W Geneva St, Williams Bay, WI 53191-9603
+1 262-245-5555
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Reviews (213)
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1 - 10 of 212 reviews

Reviewed 4 days ago

The one-hour guided tour of this historic and scientifically significant site was spectacular. The guide was very skillful in weaving the architectural, mechanical and astronomical elements of the site into his presentation. The history and stories of the personalities responsible for design, funding and construction...More

Thank ScoopMakovec
Reviewed 1 week ago

Wonderful experience for anyone even vaguely interested in stars, planets, galaxies & the people who discovered them. Many of those famous people (Einstein, Hubble, Hale, Wilson, etc.) made those important discoveries looking thru THIS telescope, once the world's largest. Even the kids (age 10-12) were...More

Thank David K
Reviewed 1 week ago

A great experience for both novice and experienced astronomers! To realize that you are looking into the same telescope that Carl Sagan did his research is pretty cool. Just seeing the size of this telescope and the building was very impressive. Dan was an awesome...More

Thank harpersm
Reviewed 2 weeks ago

Upon approaching the Yerkes Observatory, all signs tell that the building itself and its interior will hold an astonishing adventure. The years 1895 are carved into the stone lintel above the door; the building's use began in 1897 though the housing for the telescope was...More

Thank midwest52016
Reviewed 2 weeks ago via mobile

A truly amazing experience, the moon and stars were truly unbelievable. Our guide Dan was extremely knowledgeable when it came to the observatory as well as astronomy. We were treated to a rare view of Neptune and saw stars and clusters of galaxies as far...More

Thank Steve F
Reviewed 3 weeks ago

The tour covered the history of Yerkes the man and the Observatory, and the forty inch refractor telescope's place in the world of large telescopes. Perhaps a bit too much is told about the architectural decorations on the building, but some may find that interesting....More

Thank JamesRobinsonLowe
Reviewed 3 weeks ago

We visited Yerkes while in Lake Geneva for a weekend getaway, and we were not disappointed. Beautiful building and grounds, very interesting history and tour. Would love to come back for evening observing through the 40-inch! Above all else, great to visit a filming location...More

Thank Cliff J
Reviewed 3 weeks ago via mobile

We attended an evening observing session on a beautiful September evening and it was extraordinary being able to experience the giant dome (and floor -- the world's largest elevator!) moving into position, then actually look through the world's largest refracting telescope with our own eyes....More

Thank Steve C
Reviewed 3 weeks ago

I attended both a Saturday tour and a recent evening star party with the famous 40" refractor. Both visits were extraordinary. The history of the building is significant -- to both the Lake Geneva/Williams Bay region and to the study of Astronomy and Astrophysics. What...More

Thank ken9008236
Reviewed 4 weeks ago

At one time, late 1890's, this observatory possessed the largest telescope in the world. Surprisingly they still have the largest elevator in the world. This is a must see.

Thank DougCsr
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Questions & Answers
Mary D
23 August 2017|
AnswerShow all 4 answers
Response from SteveT6029677454 | Reviewed this property |
Thanks for your comment Mary. Important for other folks to know.
Bridget G
27 June 2016|
AnswerShow all 5 answers
Response from Dan K | Property representative |
Bridget, our tours are most appropriate for ages 6 and up. Weekday tours are structured and visitors must stay with the tour guide at all times. Yerkes is a working facility and our offices are open on the main floor and... More
26 August 2015|
Response from Dan K | Property representative | Reviewed this property |
Hi, and thanks for asking about Yerkes. I am one of the tour guides and am happy to give you directions. The Observatory is located at 373 W Geneva St (Hwy 67), Williams Bay, WI 53191. Travel west from the central area of... More