The third-largest city in Poland, Lodz's historical and global significance is largely due to the ghetto that was built there during World War II. Strolling the picturesque central streets will give you an appreciation for the strength of this city and its citizens. Explore the Muzeum Sztuki modern art museum, which houses one of the most important collections of modern art in Poland, or spend the day thrill-seeking at Lunapark amusement park.