This is a symbol that you see quite literally EVERYWHERE in Sevilla. On bike racks, drains, bus stops, street signs, manhole covers, taxis, monuments, Christopher Columbus’ tomb… everywhere.
When I did a bit of research on it, I found out that it’s Sevilla’s motto. Here’s what Wikipedia has to say about it:
The motto is a rebus, combining the Spanish syllables (NO and DO) and a drawing in between of the figure “8”. The figure represents a skein of yarn, or in Spanish, a “madeja.” When read aloud, “No madeja do” sounds like “No me ha dejado”, which means “It [Seville] has not abandoned me”.
The story of how NO8DO came to be the motto of the city has undoubtedly been embellished throughout the centuries, but legend has it that after the conquest of Seville from the Muslims in 1248, King Ferdinand III of Castile and León moved his court to the former Muslim palace, the Alcázar of Seville.
After Ferdinand’s death, his son, Alfonso X assumed the throne. Alfonso’s son, Sancho IV, tried to usurp the throne from his father, but the people of Seville remained loyal to Alfonso and this is where NO8DO was believed to have originated when, according to legend, Alfonso X rewarded the fidelity of the Sevillanos with the words that now appear on the official emblem of the city of Seville.