Canterlot Valley

Canterlot Valley
Canterlot Valley is simply the extensive, flat area below the actual Canterlot Castle. This valley is actually (by a wide margin) where the most Canterlot buildings and citizens are. The castle is merely home to the most wealthy.

The road that leads up to the castle is protected by the same spells the castle itself uses. In the event of an invasion, Canterlot's citizens could follow the road up to the castle where magic emergency facilities would await them, hopefully before the spells crumble.