Entry No. 68 — the Chicago file — filed under: roadside-oddity

Yerkes Observatory

Called the birthplace of modern astrophysics, this 1897 lakeside observatory houses the largest refracting telescope ever used for science: a 63-foot, 12,000-pound instrument with 40-inch lenses, so finely balanced it can be swung by hand. Einstein visited, and Edwin Hubble and Carl Sagan worked here. The University of Chicago handed it to a local foundation in 2020, and after restoration it reopened for daytime tours and night-sky telescope sessions on its Olmsted-designed grounds.

The move: Book a night-sky tour, stand under the great hand-balanced refractor, then take turns at the eyepiece on a clear evening over the lake.

📍 Before you go Tours run select days (typically Tue/Fri/Sat) and require advance tickets; night sky tours sell out. About 80 miles northwest of Chicago near Lake Geneva.

• 📍 Williams Bay, WI
• 💸 $
• ⚡ Up for anything
• 🌗 Indoors

Where: 373 W Geneva St, Williams Bay, WI 53191

Hours: Added 2026-06-23 — confirm current hours before you go.

⚠ Seasonal or scheduled — always check before you go.

Plan a visit & invite your people →

Proof: source 1 · source 2 · source 3 · source 4

last checked: 2026-06-23