Opt for the Aeroport bus, which crosses the city, offering a visual overview along the way. The bus drops you off at Placa Catalunya, near Las Ramblas, Barcelona’s pedestrian street that is anything but. There is no better place in the country to partake in the Spanish ritual of a paseo (stroll) than Las Ramblas, which cuts a wide swath to the Mediterranean Sea. For lunch, duck into the Modernista Boqueria market, a cathedral to fresh produce; try calamari squirted with lemon and a chilled pitcher of sangria (or three).