Castle of Friendship

The Friendship Rainbow Kingdom is a kingdom that is to be gained by Princess Twilight Sparkle in My Little Pony Friendship is Magic  season four.

Development
"QUEST FOR A KINGDOM".

History
Princess Twilight Sparkle's potential future kingdom is discussed throughout My Little Pony: Twilight Sparkle and the Crystal Heart Spell, and is later discussed again briefly at the beginning(s) of My Little Pony Equestria Girls/My Little Pony: Equestria Girls: Through the Mirror.

Season four finale episodes Twilight's Kingdom - Part 1 and Twilight's Kingdom - Part 2 are named after the Friendship Rainbow Kingdom.

Merchandise
"MY LITTLE PONY fans can discover the newest royal empire inside the FRIENDSHIP RAINBOW KINGDOM castle playset, a grand three-level palace fit for a pony princess! Use the friendship keys to unlock a number of magical accessories within the kingdom, including a wardrobe, vanity, book, and treasure chest. Pony friends can travel the kingdom in style on the rolling cloud car, taking a ride down a fun swirly slide. Stops along the way include a lookout tower, golden balcony, swing, and more. Includes PRINCESS TWILIGHT SPARKLE figure, key, cloud car, and themed accessories. (Ages 3 years & up/Approx. Retail Price: $39.99/Available: Fall 14)". The playset's packaging, displayed along with it by Hasbro at the 2014 American International Toy Fair, lists its name "FRIENDSHIP RAINBOW KINGDOM" with a trademark symbol. Some promotional photos are of an alternate version of the playset, in which the first floor's interiors are instead images of the same designs as in Canterlot Castle and the design of the second floor's interior is instead the same as of Golden Oak Library's first floor.

The Keys Of Friendship DVD cover depicts the Friendship Rainbow Kingdom and Princess Twilight Sparkle.