Aveiro, Portugal. Art nouveau house facade in central Aveiro. Photo: Alamy

Halfway between Porto and Coimbra, Aveiro is a floating city full of art nouveau treasures. Aveiro’s economy still comes from seaweed, salt and ceramics, and it was the revenue from these, plus the wealth of returning emigrants who had grown rich in Brazil at the end of the 19th century, that led to requests for extravagant new residences. Take a tour on one of the gondola-style moliceiros to the Rossio district; try the local ovos moles delicacies in one of the bars where Aveiro’s particular style of arte nova includes pale-shaded tiles, ironwork balconies and floral mouldings. The Museu de Arte Nova is in the Casa Major Pessoa on Rua Dr Barbosa Magalhães and its first-floor tearoom, the Casa de Chá, turns into a cocktail lounge serving caipirinhas in the evening – its floral designs and tiled birdlife motifs masked by mood lighting after dark.