No trip to Windsor could possibly be complete without a visit to amazing Windsor Castle, the family home to British kings and queens for over 1,000 years.
The size of the Castle (5.3 hectares/13 acres) is breathtaking, in fact, it is the largest and oldest occupied castle in the world and it’s where Her Majesty The Queen chooses to spend most of her private weekends. You might even time your visit when she is in residence! Look at the flag flying from the Castle’s Round Tower; if it’s the Royal Standard The Queen will be there too.
Over the past few years, the Royal Collection Trust has been busy transforming the experience of visiting Windsor Castle, and visitors are already enjoying many improvements to the visitor experience.
The Moat Room, a new introductory space, now tells the story of the Castle’s 1,000 years of history. Windsor Castle’s Inner Hall, created by George IV in the 1820s as a space to receive official guests, has been restored and opened to the public. Now, for the first time since its closure by George’s niece, Queen Victoria, the Inner Hall serves its original purpose as a magnificent welcome area for visitors to the Castle. The medieval Undercroft has now been transformed into the Castle's first permanent café.
https://www.windsor.gov.uk/things-to-do/windsor-castle-p43983