Porto (also known as Oporto) is the second-largest city in Portugal, with a population of around 220,000. Among the architectural highlights are the cathedral, the Gothic Church of St. Francis, the city walls and a number of 15th-century houses. From the 13th century, wine produced in the Douro Valley was transported to Porto in barcos rabelos (flat sailing vessels). By the 18th century, the production of Port wine had passed into the hands of a few English firms. From Porto’s riverside quays, dried fruits, nuts and olive oil (as well as Port) were exported to the Old and New worlds. Today the Serralves Museum of Contemporary Art, the art deco Coliseu do Porto concert hall and Livraria Lello, one of the world’s most beautiful bookshops, are all integral to the city’s cultural life.