Kelvedon Hatch is a village and civil parish in the Borough of Brentwood in south Essex, England. It is situated just north of Pilgrims Hatch, approximately to the north of Brentwood and is surrounded by Metropolitan Green Belt. The village today is no longer a rural backwater with a large proportion of its population commuting to work elsewhere. It has a population of 2,563.
It is home to the Kelvedon Hatch Secret Nuclear Bunker, the largest and deepest cold war bunker open to the public in South East England. Hidden in a wood off the A128 Ongar (now well signposted for the tourist trade), Brentwood Road, is a small bungalow (guardhouse) which hides a three-level bunker complex underground; a long corridor leads down to a place in which up to 600 people would have been confined behind blast-proof doors in the event of a nuclear war. The bunker was originally built in 1952/3 by the construction firm Peter Lind & Company Ltd, as part of ROTOR, an urgent government building programme to improve Britain's air defence network and became the Sector Operations Command for the RAF Fighter Command with responsibility for the London Sector. It subsequently became adopted as a potential 'regional government bunker' as the threat of nuclear war grew in the 1960s. The bunker was sold in the 1990s and is now a tourist attraction and film location. The bunker is currently owned and operated by the family who originally owned the land before the military moved in. It has a many historical items remaining intact including a BBC studio. A souvenir shop in the original canteen sells items, including government literature produced for the public in the early 1980s.