The interpretation of the historic changes to the semiotics of Barcelona’s urban landscape has highlighted several underlying issues. The meanings of the built environment alter with technological, social, and political changes. Signs and symbols which were obvious to previous inhabitants become opaque or unintelligible to later generations. Older messages written into the landscape also become unacceptable to emergent social groups, with pressure to correct or remove them. Perceptions of the city alter property values, and through the mechanism of gentrification lead to displacement of different social groups. Analysis and interpretation of the semiotic landscapes contributes to a clearer understanding of the interplay of different agencies in influencing the direction of large cities like Barcelona.