Cloudsdale

Cloudsdale is the cloud city located in the skies northwest of Canterlot and Ponyville and 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 cues from Greek culture, which is appropriate as the myth of Pegasus originated from Greek mythology.

Development
According to Lauren Faust, the name "Cloudsdale" was originally suggested by her husband Craig McCracken.

Sonic Rainboom
Rainbow Dash and Fluttershy visit Cloudsdale in the episode Sonic Rainboom in anticipation of the Best Young Flyer competition. It is revealed that Cloudsdale can only be accessed by Pegasus ponies. The whole city is made of clouds, which only Pegasus ponies can walk on. Twilight Sparkle uses magic to enable her non-Pegasi friends and herself to walk on clouds. Rarity, on the other hand, is given a pair of magical wings so she can fly along with them. The friends visit Cloudsdale and attend the Best Young Flyer competition to on cheer Rainbow Dash. The episode also shows facilities in Cloudsdale such as the large Cloudeseum, where the Best Young Flyer competition is held, and a weather factory where rainbows, snowflakes, and clouds are manufactured and distributed to Equestria.

The Cutie Mark Chronicles
A summer flight camp in Cloudsdale is the scene for Rainbow Dash's and Fluttershy's childhood flashbacks in The Cutie Mark Chronicles. In the flashbacks, Rainbow Dash stands up to some bullies who are making fun of Fluttershy's weak flying. Rainbow Dash challenges the bullies to a race, and at the beginning of the race, Fluttershy is accidentally knocked off a cloud and plummets to the ground. Her life is saved when she lands safely on a swarm of butterflies. Fluttershy gets her cutie mark when she realizes how much she loves the animals living on the earth below. Rainbow Dash's flashback includes the rest of the race. When she is winning, she realizes she loves speed and "winning". She miraculously performs a sonic rainboom and gets her cutie mark.

Other episodes
Hurricane Fluttershy portrays 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 Ponyville's reservoir by creating a tornado. Fluttershy is reluctant to help at first, on account of 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.

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

In The Return of Harmony Part 1, Discord shows Rainbow Dash a vision of Cloudsdale's destruction before brainwashing her. She then accepts his offer to restore her wings and then abandons her friends, believing that she is needed in Cloudsdale. In The Return of Harmony Part 2, Twilight and her friends find the grayed out Rainbow loafing on a single cloud she appears to think is Cloudsdale.

The Wonderbolts act as the delegates of Cloudsdale for the Equestria Games tryouts in Rainbow Falls, with Spitfire offering Rainbow Dash a spot on their team, due to her growing up in Cloudsdale, after Soarin is forced to drop out due to an injury.

In the Equestria Games episode, the Cloudsdale team wins gold in the Games' aerial relay event. Spike offers to sing the town's national anthem in celebration, thinking he would be singing Ponyville's anthem and, because he is unfamiliar with the song's lyrics, awkwardly improvises them on the fly.

Depiction in the comics
In My Little Pony Annual 2013, the human Rainbow Dash states that she and Fluttershy attended Cloudsdale Junior High together.

In, a sheet of paper on page 3 reads "Cloudsdale in ruin", referring to the Cloudsdale of an alternate universe.