50 Queen Anne's Gate

50 Queen Anne's Gate is an office block in Westminster, London, overlooking St. James's Park, which was designed by Fitzroy Robinson & Partners, with Sir Basil Spence and completed in 1976. It was well-known as the main location for the UK Home Office department between 1978 and 2004 and now houses the Ministry of Justice. The building is 56 m (184 ft) high, with 14 floors providing 51,000 m² (550,000 sq ft) of office space.

The site was previously occupied by the enormous 14-storey mansion block Queen Anne's Mansions which were despised by many architectural commentators, and its demolition was regarded as highly desirable. However, the new building was not favourably received architecturally either, due to its scale and massing with protruding elements at the upper and lower floors, often being described as a Brutalist design: it was sometimes known to those who worked there as "the Lubyanka". Fodor's guide to London described it as "hulking", and Lord St John of Fawsley remarked that "Basil Spence's barracks in Hyde Park ruined that park; in fact, he has the distinction of having ruined two parks, because of his Home Office building, which towers above St James's Park."Fact|date=January 2008 The building was originally built as a speculative office development but the Home Office moved to it due to lack of space in its previous headquarters in Whitehall.

In spring 2005 the Home Office moved to a new purpose-built building at 2 Marsham Street designed by Terry Farrell. The Queen Anne's Gate building had major refurbishment work carried out on it, whilst being under the ownership of Land Securities, and from Spring 2008 is the home to the Ministry of Justice, with the building renamed as 102 Petty France.