Entry No. 63 — the Chicago file — filed under: outdoor-weird
Palos Preserves (World's Largest Urban Night Sky Place)
Roughly 30 minutes from downtown, this 6,600-acre sweep of Cook County forest is the largest Urban Night Sky Place in the world as certified by DarkSky International, emitting nearly a thousand times less light than the Loop. About four times more stars are visible here than over the city, as measured by the Adler. The preserves close at sunset, but the Forest Preserves and Adler partner on stargazing nights, night hikes, and owling, and year-round camping at Camp Bullfrog Lake lets you stay out under the Milky Way.
The story
On light-pollution maps of Chicagoland, the 6,662-acre sweep known historically as Mt. Forest Island looks like a impossible black hole pressed against suburban sprawl. While the Loop radiates enough skyglow to erase nearly every constellation, this expanse of Cook County bluffs, wetlands, and oak groves holds just four buildings across its entire footprint. In 2021, DarkSky International officially designated Palos Preserves as the world's largest Urban Night Sky Place—a title reserved for rare pockets of protected darkness lingering right on the fringe of major metropolitan areas.
The proof wasn't gathered by suit-and-tie academics, but by teenagers equipped with custom gear. Adler Planetarium's Far Horizons program armed high school interns with cameras built in-house, sending them into the woods and across the city to gather ground measurements. Paired with satellite data and photos taken by astronauts aboard the International Space Station, their findings proved Palos emits nearly 1,000 times less light than downtown Chicago, revealing roughly four times as many stars as you can spot from the lakefront. To keep it that way, county officials retrofitted the few buildings and lots on site with downward-shielded LEDs, motion sensors, and strict timers.
What it's like
Do not try sneaking into a trail parking lot after dusk; forest preserve police actively patrol the gates, and general access snaps shut right at sunset. If you want to sit under the stars legally, you have two legitimate backdoors: book a campsite at Camp Bullfrog Lake (9600 Wolf Rd) or register for a night hike, owling session, or telescope night co-hosted by the Forest Preserves and Adler. Manage your expectations on absolute blackness—local stargazers point out that you will still spot a faint orange skyglow dome pulsing on the horizon, but if you pitch a tent at Bullfrog Lake on a clear night, you will catch constellations, satellite passes, and meteor trails invisible anywhere else in the county.
The move: Reserve a campsite at Camp Bullfrog Lake or join a partnered stargazing night, then lie back and count constellations you can't see from the city.
📍 Before you go Preserve closes at sunset for general access; after-dark visits require a stargazing event or a camping reservation at Camp Bullfrog Lake.
- 📍 Palos / Willow Springs
- 💸 Free
- ⚡ Up for anything
- 🌗 Outdoors
Where: Camp Bullfrog Lake area, 9600 Wolf Rd, Willow Springs, IL 60480
Hours: Added 2026-06-23 — confirm current hours before you go.
⚠ Seasonal or scheduled — always check before you go.
Pair it with
- Resurrection Cemetery (Resurrection Mary) — Follow Archer Avenue northeast from Willow Springs to pass the iron gates famous for Chicagoland's most enduring 1930s hitchhiker ghost legend.
- Bachelor's Grove Cemetery — Head eight miles east to Rubio Woods to hike the overgrown path leading into Chicago's most famous abandoned, heavily rumored burial ground.
- Keepataw Preserve Lime Kiln — Pair an evening at Camp Bullfrog Lake with a daytime trail trek to a ruined 19th-century limestone quarry kiln hidden in nearby Romeoville.
- Cernan Earth and Space Center — Trade real-sky stargazing in the Cook County woods for an indoor planetarium dome show named for Apollo 17 moonwalker Gene Cernan.
Good to know
How dark is Palos Preserves compared to downtown Chicago?
Data collected by Adler Planetarium shows the preserves emit nearly 1,000 times less light than downtown Chicago, allowing you to see about four times as many stars overhead.
Can I visit the preserves late at night just to stargaze?
No. General forest preserve grounds and parking lots close strictly at sunset. Night access requires an advance camping reservation at Camp Bullfrog Lake or registration for an authorized evening event.
How can I stay out past sunset legally?
You must either reserve a campsite, cabin, or RV pad at Camp Bullfrog Lake or sign up for a guided night program like a stargazing night or night hike.
How big is the protected dark sky area?
The Urban Night Sky Place designation covers 6,662 acres within the Palos Preserves, making it the largest certified urban night sky site on the planet.
Plan a visit & invite your people →
Further reading: fpdcc.com · darksky.org · idachicago.org · Reddit
last checked: 2026-06-23