In a chapter of The City of Marvels, Eduardo Mendoza says there are no more gregarious people than the Catalan people. I would extend it to most countries of the Mediterranean basin, because while we are part of this region linked (or separated) by the Mediterranean sea, I agree that we Catalans like to live together. Is for this reason, that the center of many cities, which usually corresponds to the original urban core, is composed of sections of irregular streets and buildings as high as the construction technique of the time allowed.
The Barrio Gòtic, and Ciutat Vella in general, are a good example of these narrow urban streets and even narrower passages, probably due to the local gregariousness we are talking about.
Metro L1 (Catalunya) | L3 (Liceu) | FFCC (Catalunya)