The apartments of Prince Józef Poniatowski (aka 'the Tin-Roofed Palace') are also open to the public, though a separate ticket is needed (30/20zł, open Wed, Sat, Sun only), and includes his surprisingly cerulean bedroom and grand collection of paintings. This section of the Royal Castle is open from 10:00-17:00, Tuesday to Sunday.
Some of the halls are reputed to be intermittently haunted by a ‘white lady.’ According to legend her appearance signals imminent disaster. The nearby chapel boasts an urn containing the heart of Polish hero and freedom fighter Tadeusz Kościuszko. Next on the tour, the Houses of Parliament. Last but not least, the opulent Great Assembly Hall has so much gold stuck to the walls it's hard to resist the temptation to scratch some off - just a bit, they wouldn't notice. Behave or get accosted by vigilant wardens and enjoy the views across the river to the Praga district instead. For those interested in the Castle's reconstruction the basement exhibition 'From Destruction to Reconstruction' details the building's resurrection after World War II rendered the place a pile of rubble. Note that this exhibition is free, so those not willing to spring for a ticket for the entire tour can still visit this section of the Castle. The east-wing also contains the Gallery of Masterpieces, which has works by Rembrandt (separate ticket required, 45/35zł). The newly renovated and re-opened 2.5h French Baroque Royal Gardens (open daily until 18:00, admission free) are very much worth seeing too. Found round the back, near the river, they have been returned to their former glory, with a modern yet elegant touch.