Crews digging a stormwater basin at Chicago O'Hare International Airport pulled something unexpected out of the ground: a 50-ton boulder, roughly 11.5 feet wide and buried about 30 feet beneath the airfield. Rather than quietly hauling it away, the City of Chicago turned the discovery into a public naming contest — and the shortlist is delightfully local.

The rock surfaced during excavation of the South Detention Basin, part of ORDNext, the airport's sweeping terminal expansion that Chicago bills as the largest in its history. Geologists identified it as dolostone, a limestone-related sedimentary rock that forms when magnesium-rich groundwater alters limestone over millions of years. Big finds like this are rare, but the geology beneath O'Hare is exactly the kind of thing major infrastructure projects have to plan around — stormwater drainage matters at an airport covered in pavement, runways and taxiways.

After nearly 3,000 name suggestions poured in from September, officials revealed six finalists on October 16, 2026: Sweet Stone Chicago, No ORDinary Rock, Chicago Rocks, O'Rock, Orchard Rock and Da Rock. Voting is open online until 5 p.m. Central Daylight Time on November 2, 2026. Crews had been calling it the "O'Hare bean" — a nod to Cloud Gate, the city's famous sculpture — so the contest is very much in Chicago's playful civic spirit.

The winning name won't be carved into the boulder. Instead, it will be displayed alongside the rock in a new airport exhibit once the construction dust settles, giving passing travellers a quirky piece of the airport's story to stumble across.

Why should a traveller care? O'Hare is a hub for United and American and one of the busiest connecting airports in the world, so the ORDNext expansion — new terminals, modernised infrastructure, better passenger facilities — will shape the experience of millions of people passing through. The boulder is a fun window into the less glamorous work happening below and behind the scenes: drainage basins, excavation and the engineering that keeps a mega-hub running. If your next connection takes you through ORD once the expansion opens, keep an eye out for the exhibit. You may be standing next to the city's newest — and oldest — attraction.

Voting closes on November 2, so if you fancy backing "Da Rock," the clock is ticking.

Story via Simple Flying.