The More Outlandish Theory Being that it was Nightmare Moon Enacting Revenge from Beyond the Planet

This hoofnote is about Roan, which I know we haven't seen as much of as other cities. Hey, they've been preoccupied.

Roan is the oldest city that still stands in Equestria, having been completed more than two-thousand years prior to events in this story. It started life as a forest village, one of hundreds that were cropping up across the country in the wake of Discord's deposition by Celestia and Luna. Where most villages failed outright or simply never grew, Roan managed to thrive. It was built close to Eyehole Delta, a large and fertile area at the very end of the Whitewater Stampede, the same river that would give Applewood its electricity centuries later. Unlike the northern areas along the river, which were known for deep, rapid waters, the waters that fed Eyehole Delta (so named for the narrow alluvial fan between shallow valley walls, nearby) were temperate, allowing for easy trade along the river there. The village's proximity to Celestia and Luna's birthplace was a pleasant coincidence, which would help the original tourism economy later.

As more of the forest was cut to fuel Roan's growth, ponies found more and more deposits of natural resources, most notably gold (bits at that time were still made of gold, not harder metal). Quarries appeared, and unicorn labor began to become commonplace, with magicians boring holes in rock or carrying massive loads of materials. There were no machines; technology was at a standstill at that time.

Eventually, Celestia and Luna would move to the city with their friends, who would all help to form the first royal court. They had no intentions of assuming royalty at the time, but it was not long before their magical expertise and knowledge of Discord, whom many ponies believed to be still out there and simply biding his time, elevated them above the common ponies in the town. They gave advice, both magical and benign, and were among the first ponies to be paid in currency for it, most ponies at the time operating on a barter system. As the years went by, their advice-giving became a business, and their house became an office, prompting its enlargement. It would later be torn down to make room for more contemporary architecture, and the royal sisters would move into their first castle.

There, the advice stopped being on topics of domesticity or triviality. The royal sisters and their court were asked to render their thoughts on border concerns, the use of magic in industry or medicine, and the overall development of a society that was, to everyone at that time, completely new. The minotaur nation, directly south, had many ponies nervous, as did the griffons to the far west (the border between the two countries running longitudinally right around present-day Appleloosa).

Tension between countries grew, and at the same time as the princesses (the formalizing of their title taking place right at the beginning of the second millennium) were experimenting with magically prolonging their lives, construction began of a castle several thousand miles northeast of Roan. It was the first of many along Equestria's borders, and the princesses would relocate there to oversee the country's defense from the east. Roan, meanwhile, retained its vitality on trade and tourism. When a peace treaty was made with the minotaurs a decade later, it would benefit from that, too.

Two hundred years later, and from yet another castle, this one in the Everfree Forest, Luna succumbed and became Nightmare Moon, prompting Celestia to banish her. The news shook the country, and Roan in particular, having been founded close to the princesses' birthplace and then reared by their wisdom. The prosperous city lost a third of its population in a mass exodus into the nearby woods and mountains.

Then, six years later, disaster struck in the form of an earthquake. Many blamed it on the overabundance of quarries and mines from which the city was constructed. The common (and correct) theory is that the ponies dug too deep and too close to a subduction zone and destabilized the bedrock on which much of Roan was built, until, centuries later, it gave way. Eighty-five percent of the city, including the princesses' castle, fell nearly one hundred-fifty feet into a wide sinkhole. Celestia would honor the tragedy by personally burying the ruins under half a million tons of sanctified earth, which she needed to levitate in four batches.

The city was not to be forgotten. Those that remained did so with bitter determination to see Roan recover, and began laboriously rebuilding businesses and infrastructure. By the year 2600, three hundred years after Nightmare Moon's imprisonment, Arbeit Mansel (the Middle Equestrian name equivalent to Valued Idea) moved a prosperous opium and poppy seed smuggling operation to Roan, believing the more out-of-the-way and disenfranchised town would be a better hiding place. Like the princesses before, he and his siblings grew in wealth and power, allying themselves with other wealthy and criminal ponies across the country, and branched out into more legitimate ventures. Within the next fifty years, they had established permanent roots in Roan under the banner "Mansel and Friends," and Roan's recovery is due in no small part to their influence.

As the city grew and eventually succeeded its former size, ponies decided to make use of the ruins below to expand, instead of building upwards, which was too daunting a task at the time. Mines and tunnels were more carefully dug, and portions of the ruins were excavated either to be reused or to help a slacking tourism industry. Most, however, remained buried as ponies simply hollowed out a space beneath the city. Two billion bits were spent to make sure the caverns were dug safely and maintained. It was in these caverns that the Mansels, again wishing to be less immediately visible to the public eye, set up the majority of their living spaces and businesses.

In the present day, Roan has become known as the oldest city in Equestria and renowned for its cultural diversity and architectural antiquity. It is the second most visited city, after Applewood, of course. Under the ground, however, the old bloodlines still prosper off the fat of the city above. Of these, the Mansel family is the most powerful and most feared, its roots running deeper than all, just as the Astras in the north, their professional rivals. Clashes between the families are frequent, and often take place in the form of political conflicts between members of the royal court, where both families exert powerful, unseen force.