After visiting Windsor Castle and Chatsworth House (Darcy Estate), we then visited Buckingham Palace.
If you could only visit one palace in the UK, it would have to be Buckingham Palace.
Photography is not allowed inside the royal palaces, as is the case with Windsor Castle, so we could focus on the guided tour.
The gift shop after the Buckingham Palace tour has some limited-edition items available only there, making great souvenirs.
I bought a Buckingham Palace + Royal Horse Stables combo ticket. The product page stated that visiting the Royal Horse Stables allowed direct entry to Buckingham Palace, but this wasn't actually the case.
The State Rooms and the Royal Horse Stables are exchanged at two separate locations, not far apart. However, the ticket exchange and verification are handled by different people, and the verification personnel strictly adhere to the reserved time.
The Royal Horse Stables houses the Golden Carriage used exclusively for coronation ceremonies, which is worth seeing; there are also carriages for tourists to ride in and take photos.