Queen Anne's Mansions was a block of flats in Petty France, Westminster, London, at grid reference TQ296795. In 1873, Henry Alers Hankey acquired a site between St James's Park and St James's Park Underground station. Acting as his own architect, and employing his own labour, he proceeded to erect the first stage of the block. At twelve storeys, later increased to fourteen, it was the loftiest residential building in Britain.