Walking in Spain, Not In the Plain

We have been in Granada, Cordoba, and Seville, and have had a great time wandering around the narrow and varied streets of the older parts of these cities.   It is interesting to reflect on how different this is from most of North America, where we live in newer neighborhoods that are mostly defined by streets that follow a rectangular grid.  In the case of the older cities, you have street patterns than are seemingly determined by random human impulses, as opposed to the modern, rational thought of urban planners of the last few centuries.  Just what determined the particular shapes and directions of the narrow and constantly curving directions of the streets in these old Spanish towns?   I'm sure someone has done research.   But, as a walker, why do I love these irregular and confusing streets?
Even when I have no clue as to where I am going?
In Grenada, we stayed, on the edge of the old Moorish quarter, Albacin, a hilly neighborhood where many of the "streets" are not wide enough to accommodate cars.   The same held mostly true for Seville and Cordoba; mazes of narrow streets that defy logic, and yet are absolutely human.  Our hotel in Seville was on a street about 3 feet wide; hence all deliveries, etc.  could not be done by car or truck.   Very human, and very quiet without the sound of motorized vehicles.

Wandering through these cities there was always something to see.

Vera in the streets of Granada:

Granada by Night:

A nice place to sit?

And suddenly, a religious procession, with lots of incense;