"It had several towers, each higher than the next, a large dome in the center, and a gigantic clock just above the newly built front steps."
Queen Red Riding Hood’s new castle is the main location in the Red Riding Hood kingdom. It was built after her old castle burned down, and is described as "twice as tall and wide" as the old one. It is built to resemble the other Queens' castles and palaces.
The castle has large red doors, marble floors, golden pillars, and many portraits of Red. The floor has tiny basket-shaped tiles connecting the corners of the marble tiles.
Queen Red's Chambers :
"Queen Red's new bedroom was twice the size of the twins' rental house. There was a diamond chandelier hanging from the ceiling; large, colorful and cushiony furniture lined the room; and the biggest four-poster bed the twins had ever seen- large enough to sleep ten comfortably- was on its own platform in the back of the room."
The closet is equally impressive and looks like a ballroom to the twins. It has a wall of mirrors and golden chests holding thousands of clothes and accessories.
Froggy's library : After Froggy moves in with Queen Red, she has a library room built in her new castle for him. It holds the books Alex gave him, among many others.
"Shelves stretched to the tops of the very high ceiling, with ladders and balconies on various levels. A group of armchairs and sofas was placed in the center of the room near a large fireplace with a gigantic wolfskin rug (that had once been the Big Bad Wolf himself). A beautiful chandelier hung in the center of the room, giving an abundance of light perfect for reading." 
Red has a sign put up that reads "Library, place of books", and Conner ironically comments it is to remind her what a library is for, though it later turns out she has been reading some of Froggy's and Alex's books (such as Shakespeare).
(Former) Hall of Progress : a large hall in the castle used, in Beyond the Kingdoms, to hold Froggy and Red's wedding. It can hold seats for five hundred people and a two-hundred-piece symphony. It is both referred to as the 'former' Hall of Progress and simply 'the Hall of Progress'.