Poland’s lovely Baltic Coast area is highlighted by the Trójmiasto (Tri-Cities) of Gdansk, Gdynia and Sopot, all lying within about a 15-mile stretch along the west side of Gdansk Bay. Of the three, Gdansk is the biggest and most historic, Gdynia is the newest and most modern, and Sopot is the smallest and most exclusive. The towns are linked by frequent trains, and make for a terrific trip triad. As an added bonus, both Gdansk and Gdynia are linked by ferry service to northern neighbor Sweden.