Inspired by comic-book culture, Pop art, psychedelia, the space race, sci-fi, Constructivism and Buckminster Fuller, the hugely influential British collective Archigram was the epitome of 1960s avant-garde architecture. Their self-published, lo-fi but materially ingenious magazine Archigram, begun in 1961, announced their ideas for such visionary concepts as "Walking City," "Plug-In City" and "Instant City." It also served to connect the international avant-garde of the 1960s. Archigram forged links with the Metabolists in Japan, Frei Otto, Utopie and Haus-Rucker-Co in Europe, and Buckminster Fuller in the US. They were also championed by critics such as Charles Jencks and Reyner Banham, who brought Archigram's famous fourth pop-up issue to the US in 1966. Today Archigram is one of the rarest major small-press publications of the 1960s, with individual issues selling for a minimum of $600.