Updown Court (grid reference SU944641) is a Californian style residence situated in the village of Windlesham in Surrey, England. The 103-room mansion has 58 acres (230,000 m2) of landscaped gardens and private woodland. It was, in 2005, the most expensive private home on the market anywhere in the world, having been listed for sale with estate agencies Savills and Hamptons International for in excess of £70 million (US$138 million).