One of the most stunning rooms in all of Chatsworth is the Painted Hall (seen here at Christmas time). When they were looking for a site worthy of Austen's description of Mr Darcy's home, Pemberley, Chatsworth was chosen partially due to this grand room. See cheesy youtube video below for a short clip of the hall.
The most noticeable aspect of the Painted Hall is the booming colours that engulf you as you walk in. The ceiling has a Louis Laguerre mural of the allegorical ascension of Julius Caesar. Laguerre also painted the upper walls (Sistine Chapel style) with scenes from Caesar's life. The floor is inlaid with black and white marble to further submerge guests into a sea of aesthetic overdosing.
The Hall has gone through many changes over the years, but the most notable and unfortunate has been the grand staircase. Of course it looks wonderful, but it doesn't really make sense. There is actually a doorway right below it and the stairs take up a good amount of space. In Georgiana's time it was actually a horseshoe set of stairs. These took up minimal room and set a graceful curve in a room full of sharp geometric angles. Between the stairways was the entrance to the grotto; take the stairs up and you were brought to the Great Stairs with its grand murals. For whatever reason, her son Hart destroyed these stairs and replaced them with a wooden staircase. He made many improvements to Chatsworth but this was one that even he regretted. He added in walkways to define the two-story height of the hall and awkwardly connected them to a bulbous stairway. When the 9th Duchess, Evelyn came to live in Chatsworth she set to work bringing the Painted Hall back to it's original splendor. She didn't include the Horseshoe stairway unfortunately, but she knocked down one of the balconies and replaced the stairway to something more harmonious and that is what we have today.