Firbourne House was a hotel not very far from London. Donna Noble and her mother and grandfather went there for Christmas in 2008, when Donna won a trip to the hotel on a raffle ticket she found after Jival Chowdry laid her off. When they were there, the spacecraft Titanic crashed into Buckingham Palace in an alternate timeline. (DW: Turn Left)
Behind the scenes
The house portraying Firbourne House, Egerton Grey Country House Hotel, was also used as Lavender Lawns in The Sarah Jane Adventures episode Eye of the Gorgon.