Cloudsdale

Cloudsdale is the cloud city located in the skies somewhere above Equestria, and is the hometown of Rainbow Dash and Fluttershy. It is featured prominently in Sonic Rainboom and briefly in The Cutie Mark Chronicles. The name's suffix, "dale", is an old word for a valley or open river valley, but the name is also a play on the Clydesdale breed of horse. The city's buildings and general design take clues from Greek culture, which is appropriate as the myth of Pegasi originated from Greek mythology.

Sonic Rainboom
Rainbow Dash visits Cloudsdale in the episode Sonic Rainboom where she meets old acquaintances of hers from flight school. Unlike Ponyville, Cloudsdale is only home to Pegasus ponies, as the whole city is made of clouds, which normally only Pegasus ponies can walk on. Twilight uses her magic to allow her friends and herself (with the exception of Rarity who instead gets ornate wings in a much more difficult spell Twilight uses) to walk on the clouds in order to cheer for Rainbow Dash as she enters the Best Young Flyer competition. This episode shows facilities such as the Cloudosseum, where the Best Young Flyer competition is held, and a weather-making factory, where rainbows, snowflakes, and clouds are made for the needs of Equestria.

The Cutie Mark Chronicles
Cloudsdale is briefly featured in the flashbacks of Rainbow Dash and Fluttershy in The Cutie Mark Chronicles, as the location of their summer flight camp. Fluttershy's flashback shows her having difficulty flying, and accidentally being knocked off a cloud by Rainbow Dash and falling from Cloudsdale to the ground, but landing safely on a swarm of butterflies. Fluttershy gets her cutie mark when she realizes how much she loves the animals. Rainbow Dash's flashback shows her racing a couple of Pegasi who bully Fluttershy, and she accidentally knocks Fluttershy off a cloud at the starting line, but doesn't seem to notice this. While she's racing, Dash realizes she loves speed and "winning", and she performs a sonic rainboom and gets her cutie mark.

Other episodes
Spitfire briefly mentions Cloudsdale in The Best Night Ever after spotting Rainbow Dash, commending her for her actions in Sonic Rainboom.

Rainbow Dash is also shown to have a great love for Cloudsdale. This served as a breaking point in The Return of Harmony Part 1 when Discord told her that her home would crumble without her and offered to restore her wings. She accepted the offer and left, believing that she was needed in Cloudsdale.

Hurricane Fluttershy focuses on the annual task of delivering water to Cloudsdale, in order for the weather factory to produce the year's rain clouds for all of Equestria. When Ponyville is chosen for the year's delivery, Rainbow Dash and the town's other Pegasi must funnel water from its reservoir by creating a tornado. Fluttershy is reluctant to help at first, due to her weak flying skills and the taunting she endured at Cloudsdale's flight camp (as seen in a flashback). However, she eventually joins in the effort and delivers the final push needed to get the water to Cloudsdale.

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