Roissy France is 30 odd Kilometers NE of Paris near Charles De Gaul airport. De Gaul airport did not exist in 1950 which was when O was written and published. The Town was out in the country, now it is a midsized city.

Chateau and Chateau de Roissy societies are abundant and can be searched for on line. A google search of Roissy France will yield a lot of aeroport info.

Yours
Mad Lews