The carefree atmosphere, relaxation, peace and quiet of the beach can also be found in some of Spain's cities where the sea is just a few stops away by underground train. The local networks of Bilbao, Barcelona and Valencia connect - or maybe 'disconnect' - the bustle of the city with quiet days out with sun and sand. The most cutting-edge metro has to be that of Bilbao, designed by the English architect Norman Foster: if you want to take a dip in the Cantabrian Sea, in the Bay of Biscay, you simply need to step into one of the striking glass tubes known as "fosteritos" that mark the station entrances and take line 1 to the beach at the seaside village of Plentzia. In Barcelona, the stations of Ciutadella, Bogatell, Poblenou, Llacuna, Selva de Mar and El Maresme all let you out at points along the four kilometres of urban beach; without doubt, though, the train to La Barceloneta, one of the most popular places of cosmopolitan Barcelona, is the one that will be full to overflowing, especially in summer. In Valencia, the famous beach immortalised in the paintings of Joaquin Sorolla, is only a few stops from the city centre. Just take line 4 or 6 to the coast and enjoy the beaches and of La Malvarrosa and El Cabanyal or take a stroll down the promenade.