The central pedestrian artery and people-watching event in the city, La Rambla is Barcelona's best-known and most historic promenade. Lined with a succession of newspaper and magazine kiosks, bird merchants, and outdoor florist stands, festooned with colorful signs and lurid paraphernalia of every description, the Rambla is a rainbow of a street roaring just over 1 km ( 1/2 mi) through the heart of the Ciutat Vella -- the Old City -- from Plaça de Catalunya past the Boqueria market and the Liceu opera house to the Christopher Columbus monument at Portal de la Pau at the edge of the Barcelona port.