A small fishing village until the 20th century, Gdynia was rapidly built into Poland’s largest and busiest sea port after World War I. As a result, it’s mainly a very modern city. The most significant older attraction is the 13th-century St. Michael the Archangel Church. Two museum ships in the harbor, a destroyer and a frigate, are also popular with visitors. Gdynia has a thriving cultural life and in September hosts the annual Polish Film Festival, sometimes called the “Polish Cannes.”