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Thames House: MI5’s HQ
Thames House, a neoclassical behemoth on the north bank of the Thames, has a dual reputation: part historic architecture, part enigma. Located on Millbank, it’s hard to miss with its imposing design and close proximity to the Houses of Parliament. This Grade II-listed structure is the headquarters of MI5, the UK’s domestic security service, making it one of the most secure—and secretive—spots in London.