Fifty years ago, when the dictator died, Walden 7 (1970-1975) was completed in Sant Just Desvern. A project by the multidisciplinary Taller de Arquitectura, directed by Ricardo Bofill, it initially comprised 445 apartments with communal spaces, forming a kind of mega-structured city in space. The complex was made up of 30-square-meter modules that could be combined and transformed. It was the tip of the iceberg of cultural and artistic movements; one of the fruits of May '68, planned and managed in the final years of the Franco regime with an eye toward the transition to a democratic society.

"This building is like a Bach fugue." Anna Bofill means it, and she will explain it later, sitting on one of the benches in one of the four blue courtyards of the building she helped build from the Taller de Arquitectura. We are in Walden 7, this great mass in Sant Just Desvern that stands out from the highway and most people know only from hearing about it or from photographs. It's cold, and the interior is somber and imposing. It's no wonder some compare the building to a cathedral, perhaps Baroque like the musician, because in these ground-floor communal spaces there is a clear—and perhaps too obvious—desire for monumentality. But they achieve their effect. They are imposing, they fascinate. The apartments will be another matter later, which are of different types but in many cases cozy and, surprisingly, bright.