When the castle was built atop the hill, the original city of Edinburgh grew on this ridge, reaching down in a ribbon of development toward the Abbey of Holyrood, at the foot of the hill in the east.
The castle was built on the hill to protect them from the Vikings.
mnli hypothesis: The castle was built on the hill to protect them from the Vikings. premise: When the castle was built atop the hill, the original city of Edinburgh grew on this ridge, reaching down in a ribbon of development toward the Abbey of Holyrood, at the foot of the hill in the east.