"Aha! You would be right of course, but Canterlot, is no ordinary city. Judging by its shape you could assume its development was planned in advance to be radial, centered around the city hall. Usually cities are built around citadels and castles, this is the common logic of the times when inhabitants faced the danger of an attack fairly often. So, if that would be the case, the centerpoint of the circle would be the castle itself -- the suburbs would be built around it and evacuated in the case of danger.

Canterlot, however, was the testbed of development for large-scale magical shielding technology. Now, one thing that is common in all of the magical barriers is that they tend to take the form with the least surface area per unit of volume, that is, the sphere. So, when Celestia decided to split off a settlement for the inhabitants of Canterlot, she decided that by placing the settlement separately and giving it a barrier generator of its own, the area it protects could be used to the fullest. Indeed, if the barrier was situated in the castle, all the area on the cliff side would simply be wasted! About half a millenia forward the defensive aspect lost its importance but the structure of the city was well estalished by this point.

Canterlot was a first in several other aspects. It was built on a rocky plateau which was gradually cleared out with highly concentrated with magically powered gridfire, As the city grew and developed districts, special attention was devoted to interconnection of the districts, avoiding the common problem, when rich are locked in their district, poor in the other, and the city falls apart along this lines. Radial highways circle the city, providing speedy transit around it. Furthermore, each district has a hall of its own, and these halls are placed on the same transit line. The idea is to provide a space for mingling together, where ponies of different races, status and social strata can bump into one another. I'd call it a serendipity-maximization strategy...

-- Serendipity? Is that even a word? -- asked one of the ponies, listening to the beige, red-maned filly.

-- It totally is! It means "a fortunate coincidence" or "finding something you never knew you needed" or something along this lines. -- chimed in a purple-coated filly with a dark blue mane. -- Wow, you do really know a lot about Canterlot!

-- Well, I've lived there all my life. -- admitted the beige pony. -- What about you, what brings you here?

-- I'm going to study in the Princess' School for Gifted Unicorns! -- purple filly was brimming with excitement.

-- Oh. You must be smart, then. Well, welcome aboard then.

-- Thanks... Can you, by chance, show me around? I've never been to Canterlot before.

-- Sure. Hey, what's your name?

-- I'm Twilight Sparkle. And you are..?

-- Moondancer."



And that is how it all began, with a bit of nerding out.