How many capital cities can you sail past? Lisbon is one of the few, and it is well worth it. The passage upstream from Cascais or Oeiras to Parque das Nações takes an hour or so on a flood tide. The spectacular part starts at Torre de Belem and continues past the Padrao dos Descobrimentos Monument to the Discoveries – a celebration of Portugal’s important role in naval exploration – , then under Ponte 25 de Abril suspension bridge ( the date of Portugal’s Revolution in 1974 which overthrew Salazar, which, tellingly, was until the day before, the Salazar Bridge) and generally round to port/ east and the main riverside sites of Lisbon before turning northwards to the Vasco da Gama Bridge and Parque das Nações. The city of Lisbon is well worth visiting, and deserves two or four days depending on whether or not you wish to visit museums, art galleries etc.