Chateau Langley is a medieval castle that is given to Trashelle to sell on the show Langley Dollar Listings in the episode of the same name.
As she notes on the show, it has 24 bedrooms and overlooks the Langley Ravine, nor has it been on the market in 780 years, which Steve notes places it before Christopher Columbus landing in America.
When Trashelle goes missing, The show has an open casting call and Francine is selected to replace her. Roger, jealous that he wasn't selected, tries to sabotage her listings but ends up helping her and she is given the Chateau Langley to sell. Roger tries to intimidate Francine into quitting and accidentally shoves her over a balcony overlooking the ravine, which he had done to Trashelle that resulted in the show opening to begin with.
He then takes over the show from the producer in an effort to increase the show drama and ratings. Francine, who had discovered that Trashelle was alive and somewhat well, having turned her real estate skills into selling trees to the squirrels, climbs the cliff with the aid of Trashelle's high heeled shoes and confronts Roger, who tries to turn the other agents against her but are won over when they note that she is wearing Trashelle's high-heel shoes. With his plans ruined, Roger sets off the home lockdown security system, trapping Francine and the producer, who was also being held prisoner. They manage to escape using a secret passage in the chateau, but when Roger tries to throw the producer over the balcony, he is intercepted by Trashelle's fiance Tristan, who was freed by Chonkers, a fat squirrel that worked for Trashelle.
The producer ends up buying the Chateau from Francine, having started to show to have the agents look for the perfect house for him.