This is a location gallery and should therefore follow these guidelines.
Main 6 in the Chamber of the Elements.
Rarity looking toward another castle tower.
Nightmare Moon in the castle throne room.
Castle throne room, overhead shot.
Twilight in the past throne room, now with two thrones.
Hole in the throne room roof.
Elements of Harmony rise from beneath the floor.
A view of the castle from the tree Spike climbs up.
External shot of the castle from across the bridge/
Twilight and Spike in the main hall
The castle library, shot #2.
Applejack and Rainbow Dash in the Hall of Hooves.
Rarity and Fluttershy under a trap door.
Hallway lined with suits of pony armor.
Chamber of the Organ to the Outside.
Dragon statue, as seen in Princess Twilight Sparkle - Part 2.
External shot of the castle at night.
Mane 6 cleaning the throne room.
Throne room, overhead shot.
Celestia and Luna's reading room, daytime.
Mane 6 walking through castle corridor.
Castle library from another angle.
one of the library scenes
Doorway and ladder in the background
The classic book-pull-shelf-opener
A stairway leading to the book at the top
You'd think that Celestia might have warned Twilight about this before hand, it was her castle after all.
The dark staircase from a different angle
The castle is seen in the background