By OnMilwaukee Staff Writers   Published Aug 08, 2015 at 9:05 AM Photography: Bobby Tanzilo

Looking for a fun day trip and a way to get the kids jazzed about science? Why not check out Yerkes Observatory, 373 W. Geneva St., in Williams Bay, near Lake Geneva?

Situated 190 feet above Geneva Lake, the observatory is a fascinating place in a fabulously interesting building – with elaborate stone carving all over the exterior – and offers great views of the surrounding area.

A research branch of the University of Chicago's Department of Astronomy and Astrophysics, the historic building, located on a 77-acre park, serves as lab space and offers telescopes for research and teaching.

In addition, a large part of the University's astronomy library is housed there. Considerable research is conducted at Yerkes, as are many public outreach programs. For full details on these, visit the Yerkes Web site.

Though it was nearly sold by the university to a developer who wanted to build a spa resort and homes on the grounds – which were designed by John Olmsted, brother of Frederick Law Olmsted – those plans fell through.

Yerkes Observatory was the pet project of Charles Tyson Yerkes, a Chicago transportation bigwig. Yerkes financed a plan developed by George Ellery Hale, who was founder of the American Astronomical Society and co-founder of the Astrophysical Journal, which was headquartered at Yerkes until the mid-1960s.

The centerpiece of the building was, as it still is, the 40-inch refractor telescope, which is now, as it was then, the world's largest (there are actually two of them now).

When visiting the building – which is open 9:45 a.m.-1:30 p.m. every Saturday – be sure to walk the lovely park-like grounds and bring binoculars to get an up-close look at the decoration on the building's exterior. Designed by Henry Ives Cobb, the building is a product of his passion for classical mythology. Cobb's intricate ornamentation includes signs of the Zodiac, phases of the moon and all manner of unusual real and imagined animals.

Inside, in addition to tours (see below), the observatory has a gift shop and wall displays explaining – in words and pictures – Yerkes history, comets, galaxies, nebulae and the death of stars.

Inside, on the main floor, is the Quester Museum, which celebrates Yerkes astronomers who have impacted the world of science and the local community over the past 100 years. It pays special attention to the links created and maintained by Yerkes and the Williams Bay community over the years. The Quester is the fruit of the work of area volunteers interested in local history.

Tours of the observatory take place every Saturday morning at 10:15 a.m., 11:15 a.m. and 12:15 p.m., and last 45-50 minutes. There is no admission fee, but a $8 donation is suggested. Tour guides offer information on the history of the observatory, astronomical research and space.

Visitors will get a glimpse into the 90-foot dome, one of the world's largest of its kind, where the 40-inch refractor telescope is housed. Tours are intended for families and small groups and reservations are not accepted.

For groups of 15 or more, special programs are available, including viewing through the telescope, mini-classes, slide shows and talks. The charge for special programs is $100 per hour, per group. You must contact tour staff at (262) 245-5555, ext. 880, to make advance arrangements.

Yerkes has added weekday tours, too. The 45-minute tours are $8. Private hour-long tours are $100 for groups up to 50 and can be set up after 4 p.m. on weekdays, after 2 p.m. Saturdays and between 10 a.m. and 4 p.m. Sundays. Advance reservations for these tours are recommended.

To get there, take I-43 to the Highway 67 Elkhorn/Williams Bay exit. Turn south onto 67 and drive about six miles to the intersection of Highway 50. Cross the highway and continue downhill almost exactly one mile. Turn right, and go uphill, curving to your left on Highway 67/Geneva Street, almost exactly a mile up to the unlit brown sign with white lettering that says Yerkes Observatory.