Hillingdon is the second largest borough in London, and one of the least densely populated. The borough has a total of 1,800 acres of green spaces, which includes a park administered by British Airways as part of an agreement related to the building of the British Airways headquarters in Hillingdon. Two other green spaces, Frays Farm Meadows and Denham Lock Woods, are run by the London Wildlife Trust, and the Grand Union Canal runs through sections of Hillingdon.
The borough is divided into the prosperous North Hillingdon and the industrial South Hillingdon. Heathrow Airport is in Hillingdon, as are two immigration removal centres and the UK offices of several airlines. Cadbury plc also has head offices here. The Northolt RAF (Royal Air Force) station in Hillingdon has recently been expanded and is also used for private flights.