My take on Equestrian geography · 7:19pm Mar 2nd, 2021
(Note - the ideas here are evolving. Comment welcome.)
While the canon map has a fairly "vertical" Equestria modelled on North America, my vision of it was always more horizontal, covering much of a great northern continent with it's main coast to the south. (Yes, I'm European - well, British.) This makes it relatively easy to break the country down into three general sections, which I'll cover in order of the spread of pony habitation as I see it.
Eastern Equestria consists of the original homelands of the pony tribes. Not all of the inhabitants left for new pastures or perished in the Windigo Winter - some survived and rebuilt various states such as Prance, Germaney, Bitaly and Wingland. Over time, however, a mix of internal problems and the advantages on offer have seen almost all of these countries absorbed into Equestria - the main exception being the proud, landlocked Duchy of Maretonia, which has found a profitable niche in being a pony state not technically under Equestrian law. Hearth's Warming is a fairly controversial festival here, though still celebrated by many.
Show-wise, we've rarely if ever seen this side of the country - it's mainly a place for ponies with exotic names and accents to come from. (One example of a story actually set here would be the book Princess Celestia and the Summer of Royal Waves, which mostly takes place in the small coastal province of Monacolt.)
Central Equestria refers to the lands between the Cantering Mountains in the west and the Great River Running in the east. The original realm of Equestria was founded within these borders, though modern-day Central Equestria has some parts it didn't - most notably the northern provinces of Mustangia and Vanhoover, won from the griffins in the last notable war with them. South of there lie the traditional heartlands of Equestria, home to the bulk of it's population - the original capital, Fillydelphia, is the preeminent city. The southern coast, on the other hoof, is mainly centred on the great port of Manehattan - another former capital, this time of the breakaway Republic named after it.
The current Equestrian capital, Canterlot, is located at the western edge of this region. It and Manehattan are the parts of it we've seen the most - others to appear include Stratusburg, Sire's Hollow and Hope Hollow.
Western Equestria refers to all lands beyond the Cantering Mountains, which served as the traditional border. About half of the inhabited part of said lands is found on a peninsula to the south, where the land extends further than it does to the east - this region is dotted with towns, the most major city being the port of San Franciscolt. Older sources call this area simply "Western Equestria" outright, but more modern ones have dubbed it "South-Western" or "Peninsular Equestria" due to the country spreading more into the lands north of there.
Going directly north from the peninsula, one finds a long "valley" of sorts between the Cantering Mountains and the vast spread of the Everfree Forest to the west. For various reasons, including the fearsome reputation of that forest, it was not until the last century or so that pony settlements began to be founded in this region (trade caravans came a bit sooner). There are still no settlements large enough to call a city, just an assortment of small towns and villages - and it was probably only with the rise of one such town to national significance lately that most Central and Eastern dwellers realised ponies had started living here at all.
Go far enough north (perhaps following the railway line) and you'll eventually reach the northern edge of the Everfree. At that point, you can go a few ways - east through the northern Canterings to Stalliongrad and the griffin border, north to an icy wasteland the recently restored Crystal Empire, or west along the path of small towns that have sprung up one after another over the last century. The first and oldest of these towns, Dodge Junction, is a contemporary of Ponyville - the nearby city of Las Pegasus is actually a fair bit older, though it's current incarnation as an entertainment resort is fairly recent. Follow the road along, however, and you'll eventually reach smaller and newer towns - culminating in the recently-founded Applooosa, which seems likely to be the last of it's kind based on treaties negotiated with the buffalo.
(The vast Everfree itself has an ambiguous status - while the original palace of Equestria's ruling alicorn sisters was located there, the country never made any real attempt to claim or manage the vast and hostile woodland, and the dwellers of the desert beyond it are even more averse to it. Therefore, it is mostly left to it's own devices - which side of it a map draws Equestria's border on is fairly arbitrary.)
Hmm. My main hangup with this arrangement is probably the way in which the area with a climate like the American Southwest is located north of the rest of Equestria -- it seems a bit odd to have a warm-to-hot desert area sandwiched between temperate lands with snowy winters and what's more or less the arctic.
Unrelatedly, what would be in the desert beyond the Everfree? Zebras?
5465271
Hmm... yes, that is a bit tricky. But on the other hand, in Party Pooped, Pinkie's train from Ponyville to the Crystal Empire does take her via Dodge Junction. (On the other other hand, it also seemed to stop in Manehattan... but that was in the part of the journey that made no sense at all.)
And no, I put zebras on another continent. The desert is the one seen in Over a Barrel, home to the buffalo. Not sure who else lives there, but there are countries on the other side...
5465295
If that detail is there to stay, it might be worth thinking about embracing the discrepancy as something noted and recognized in-universe. So, in this case, you start with a cold-temperate area, then find a warm-temperate one north of it, and then transition to subarctic or arctic past that -- how come? Is that just a localized thing, or are these sorts of transitions and patchwork climate zones common or at least not unique in the world? If the first, why? If the second, also why? What do people think about it? Does it have any interesting effects on society or ecology? And so on and so forth.
5465336
Hmm... might be worth looking into. Obviously, in a country where all weather is manufactured artificially, it's not so odd if climatic zones are also screwy... but where's the line?