The dwarves chipped and shaped the mountainous area around Rokmil for both ease of friendly travel and optimal defense capabilities. The north and south sections of the city (where the nobles and wizards live respectively) are atificially constructed plateaus above the main part of the city. There is a wide, long, and winding road leading from the main part of the city to both the higher sections. There really is no other easy means to enter these sections of the city. You either need to scale up or repel down sheer cliffs.

In the common part of the city...

The higher sections of the city have watch towers placed on them that allow them to see everything coming from the roads for many miles. Secured with eyes of the eagle for the watch, these towers have warned Rokmil of all aggressive forces approaching the city throughout it's history.