Ayuntamiento de Sevilla

This guide to the Ayuntamiento de Sevilla opens with a riddle carved above its doorway: three strange characters that Sevillanos read aloud as a Spanish phrase, though the cipher was never built to be read, only heard. You'll hear how the sounds unlock a coded message, and the family war behind it, a rift in the 1280s between King Alfonso the Tenth and his son Sancho that split Spain's towns between them while Seville stayed loyal. It follows how that thank-you found its way into the city hall's stone, and how far the same rebus has traveled since, onto manhole covers, taxis and flags across the city.