Windsor castle tickets andamp state apartmentsr r visit the largest and oldest occupied castle in the world and the place where her majesty the queen spends most of her private weekends with our windsor castle ticketsr r discover 900 years of british history at this official royal residence which is regularly used for state and ceremonial occasionsr r established in the 11th century by william the conqueror the castle has been remodelled by various kings and queens throughout the centurie