Walden 7, designed by Ricardo Bofill’s Taller de Arquitectura, is a radical statement on collective housing and urban space that marks a turning point in Bofill’s career. Prior to this project, he had explored monumental geometry and alternative housing models in works such as the Castillo de Kafka (1968) in Sant Pere de Ribes and the Muralla Roja (1973) in Calpe. His Barrio Gaudí (1968) in Reus, a fragmented housing complex with dynamic, interconnected spaces, was an important precedent, reflecting his interest in breaking with conventional urban planning. With Walden 7, the Taller de Arquitectura took these ideas to their most ambitious form, rejecting standardisation in favour of a modular yet highly organic structure. Conceived as a self-sufficient vertical city, its labyrinthine design, suspended walkways and communal terraces promote a new way of living that encourages interaction and flexibility. The building embodies a utopian vision of collective living and is a must see to understand Bofill’s architectural evolution and radical rethinking of urban space.