Windsor castle the largest and oldest occupied castle in the world is one of the official residences of her majesty the queen of england the castles dramatic site encapsulates 900 years of british history it covers an area of 26 acres and contains as well as a royal palace a magnificent chapel and the homes and workplaces of a large number of people audio tours guided tours are included in the ticket price the semi state rooms one of the best times of the year to visit windsor ca