"I was told the Empire used to be bigger," Top Spin said to Azure. "The city you see now was the part that was hidden away by King Sombra's curse, while the rest was either destroyed in the battle to free the crystal ponies, or swallowed by the frozen north after the city vanished. Of course that doesn't make sense because they need this land around the city to grow food, and there's other stuff in it, but I'm just repeating what I was told."