IWM Duxford, about 15 kilometres south of Cambridge, is the largest aviation museum in Europe and one of the best in the world. The site is a former RAF aerodrome — operational from the First World War through the Cold War — and holds over 200 aircraft in a series of enormous hangars and outdoor displays. The collection includes Spitfires, Hurricanes, and Lancaster bombers from the Second World War, Cold War jets, a Concorde, and a large American Air Museum focusing on USAAF operations from British bases.
Duxford also holds regular air shows in which many of the aircraft fly. Admission is expensive (around £25 adults) but the scale is exceptional — allow a full day. Buses from Cambridge city centre serve Duxford village; the museum is a short walk from the stop.