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These images show the scale, street grid, and density of the 5 towns of interest that I will visit. With the exception of reykjalid, which is little more than a cluster of tourist accomodations, the street grid density is similar despite the variation in town size. The sections show that overall, the density of towns is low compared to other small european cities.
Supposedly, Ingolfur Arnarson, the founder of Reykjavik decided the location for the first settlement by using a traditional Viking method. He dropped his high seat pillar into the ocean when he saw the coastline and settled where the pillars came to shore (wikipedia). However, given the longevity of the settlement since 973 A.D., there must have been more strategic decisions that played a role.