The Crystal Empire is the home of the Crystal Ponies. It is ruled by Princess Cadance and Prince Shining Armor and formerly Princess Amore and King Sombra.
History
The Crystal Empire was ruled for many generations by Princess Amore in peace, love, and tranquility. In a sneak attack it was taken over by the evil unicorn King Sombra, who turned it into a dark land and enslaved the Crystal Ponies. Princess Celestia and Princess Luna defeated him with their magic, turning him to shadow and imprisoning him in the ice, but not before he placed a curse on the Crystal Empire that caused it to vanish for a thousand years
Population
Crystal Ponies
A kind of ponies which inhabit the Crystal Empire. Crystal Ponies are distinct from other ponies by their shiny, gradient manes and tails, and typically polygonal eye reflections. They have a magic unique to themselves that is based on how happy they are. They are similar to Earth Ponies in their connection to the land but have special link to all things crystals. They raise tiny ewes for their colorful wool and grow crystal based crops. They seem to be immune to the effects of the cold but are much happier living inside the magic dome of warmth around the Crystal Empire.
Places
The Plaza
The Plaza lies at the center of the Empire, where the Crystal Palace is located. In the series, it is a peaceful place with a lot of buildings and working Crystal Ponies. There is a snowflake pattern on the ground, spreading out from the Crystal Heart. It is the location of the Crystal Fair when it’s going.
The Crystal Palace
The Crystal Palace is the home of the royal rulers of the empire. It has a huge crystal tower which fires a ribbon of energy into the sky whenever the Crystal Heart below is powered. As well as housing for the royalty and staff there are several libraries, many meeting rooms, a large kitchen, ball rooms, storage and a bowling alley.
The Crystal Stadium
Near the Palace is a huge stadium, on one occasion used to host the Equestrian games. It is a huge structure, capable of seating many thousands of ponies in the wrap-around grandstands. As well as regular seating, the stadium also features a special seating box for VIP spectators, including customized seating for the Alicorn Princesses. It has state of the art training facilities for athletes as well as medical centers and dozens of locker rooms.
The Crystal Empire Public Library
The Crystal Empire is home to an immense library with decorative griffin statues outside its front doors. Amethyst Maresbury serves as its librarian. It is a huge repository of information about the Empire's history, as well as Equestria in general. All of it’s books are over 1000 years old so it’s a huge draw for ponies looking for rare books.
The Crystal Spa
Princess Cadance’s patronage has popularized the local spa. One of the spa's signature luxuries is a crystal mud bath.
Holidays
The Crystal Faire
The Crystal Faire is a celebration established by the Crystal Empire's first queen and is the Crystal Ponies' most important tradition. It features Petting Zoos, Jousting Competitions, Crystal Berry Treats, Crystal Flugelhorn Music, and The National Anthem was sung. Decorations included the flying of the Crystal Empire flag and the exhibiting of the Crystal Heart. The whole purpose of the Crystal Faire is to lift the spirits of the Crystal Ponies, so the light within them can power the Crystal Heart, so that the empire can be protected.
Hearthswarming
This is a new holiday in the Crystal Empire brought in by Shining Armor and Princess Cadance.