Porto is best explored on foot, though the hills are punishing. Start on the riverfront at Cais da Ribeira, walk the Dom Luís I bridge across the Douro to Vila Nova de Gaia for a port cellar tour and a view back at the tiled facades climbing the opposite slope, then lose yourself in the tangle of the old town above. The Livraria Lello is the city's headline bookshop; Casa da Música its headline concert hall. Serralves, further west, is one of the best contemporary art museums on the Iberian peninsula.