One of the people I follow on Twitter posted about annoying her daughter by referring to the My Little Pony universe as "Horsitania" (though to me, that sounds more like a doomed ship....though the MLP world being what it is, all passengers would have to be rescued at the last minute. Hm. I wonder if there's something equivalent to the Royal National Lifeboat Institute in Equestria....pegasus ponies with harnesses that would allow them to lift others from the water?)
But I proposed that "Grand Duchy of Fetlock" should be a place. (I know: most of the Equestrian cities are slightly-name-shifted versions of human (mostly US) cities: Fillydelphia, Baltimare, Trottingham....) But I'd love to see the Grand Duchy of Fetlock... with its dowager duchess, and a Disraeli-esque Prime Minister....and one of the horses would have to have a roaring mouse as its cutie mark.
And they'd probably try to invade one of the other lands, only to find all of its inhabitants were off at the Summer Sun Celebration or somesuch.
(Yes, I know "the book is different" but it's the film I am most familiar with.)