An unveiling of some of the many secrets held by Buckingham Palace, including its former rat problem, and the part it played in Charles and Diana's courtship.
Historian Jonathan Foyle casts his eye over Balmoral.
Some dramatic events have taken place at Windsor Castle, which was built more than 900 years, guided by Edward III and his obsession with tales of Camelot. There is a look at one of the most popular exhibits at Windsor - Queen Mary's Dolls' House - and Kate Williams revisits some of the castle's darker times, including the year when bubonic plague caused Queen Elizabeth to isolate at Windsor, and the death of Prince Albert in 1861.
Sandringham in Norfolk was purchased in 1861 for the rakish Prince Edward, to curb his ways, but it proved to be the perfect palace for a party.
Highgrove House in Gloucester is the smallest royal residence currently in use, with nine bedrooms. It is Prince Charles's own creation and features a garden described as an 'organic oasis'.
Kensington Palace has been home to many Royals since the 17th Century. Christopher Wren expanded Nottingham House into a palace, which some describe as a bit of a 'botched job'.
Holyrood House in Edinburgh has a bloody history - Mary Queen of Scots saw her secretary murdered in front of her there, and it is also where her second husband was murdered.
Hidden in Central London, the Palace of St James is the real seat of royal power. Originally built for Anne Boleyn, by the time it was finished her marriage with Henry VIII was over.