I could find nothing conclusive as to whether there is a city beneath the airport. You can't put a date on an unknown.
In plumington
they began building in 1999
You have to get to build the 30th level
NOBODY
243years to built it
Chicago's O'Hare International Airport is the largest airport in the state of Illinois. Located in the upper Northwest corner of Chicago, O'Hare covers two counties - most of O'Hare Airport lies in Cook County, however a small section of the southwest part of the airport is in DuPage County. As of 2012, O'Hare Airport is the fourth busiest airport in the world, following behind Atlanta Hartsfield, London Heathrow, & Beijing China. Recently, O'Hare acquired an additional 51 hectares, (126 acres), of land for expansion. This requires the relocation of 2,800 homes, the exhumation of 900 known graves, and the re-routing of a creek. Additionally, a further eleven-million cubic yards of landfill is required to build up an embankment. Based on percentage of delayed flights, official reports rank O'Hare as one of the least punctual airports in the United States.
a secret place
MXPX How to Build a Secret Weapon - 2007 was released on: USA: 17 July 2007 (DVD premiere)
the ccc
in south kent
There are no secret places in bear university.
There is not one.