One of Poland’s most beautiful cities, Gdansk, on the Baltic Sea, has played major roles in history, especially in the 20th-century. It was the 1939 flash point of World War II, and then in 1980, the birthplace of the Solidarnosc labor movement, ushering the end of Communist domination in Eastern Europe. Gdansk’s Old Town, painstakingly reconstructed to its Hanseatic League glory after being leveled in World War II, is a highlight. The 14th-century Town Hall houses the city’s historical museum.