Travel to Portugal by Train
Though surrounded mostly by water, Portugal does share the Iberian Peninsula with Spain.
From Madrid, one can travel into Lisbon, Portugal, easily via rail.
Portugal also sees train travel from other European countries, though such routes require multiple connections. For instance, from London, one can travel to Lisbon via the Channel Tunnel and then the French TGV. Such a trip would take over a day to complete.
You could also travel from Paris via a five-connector route. If you plan on making Portugal part of a trip around Europe, then definitely consider purchase of a European Rail Pass (for the specific region).